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The SnO2 was synthesized by precipitation method via tin chloride pentahydrate complexation with diethyldithiocarbamate then, calcined at temperatures 450, 600 and 750 °C and utilized for degradation of Sudan black B (SBB) dye. The calcination temperature 600 °C exhibited better degradation capability. Three light sources like visible, mercury and fluorescent were applied and fluorescent light exposed highest degradation of SBB dye. Degradation of SBB reached 90% with dosage of catalyst 15 mg at neutral pH 7 in 100 min. The 20 mg L−1 concentration of SBB dye was optimized for degradation but the degradation decreased at increased concentration of the dye. Synthesized SnO2 nanoparticles was characterized by SEM, XRD, DLS, EDX, zeta potential and FTIR to know their particles size, surface charge, morphology, structure and elemental composition of prepared nanoparticles. The SBB dye degradation followed pseudo second order kinetic model and Langmuir isotherm model. The impacts of factors were studied through factorial design using 18 experiments run, and interactions among different parameters were noted. [ABSTRACT FROM AUTHOR]

A new, simple and rapid spectrophotometric method was developed for determination of Sudan Black B in food products by supramolecular solvent-based-vortex-assisted-dispersive liquid liquid microextraction (SUPRAS-VA-DLLME). Extraction solvent type, volume of solvent, pH, volume of THF, centrifugation time, vortex time, and sample volume were investigated as optimization parameters of the developed method. Under the optimum conditions, limit of detection and limit of quantification, preconcentration factor and enhancement factor of the developed method were calculated to be 9.01 µg L-1, 29.73 µg L-1, 20, and 55, respectively. The developed microextraction method was successfully applied to food samples for the determination of Sudan Black B. [ABSTRACT FROM AUTHOR]

This article discusses a study on the lipid production capacities of two strains of Bacillus bacteria isolated from soil. The study found that these bacteria have the potential to produce lipids, which are valuable raw materials for biodiesel and other compounds. The strains were grown in specific media and subjected to different lysis methods for lipid extraction. It was found that one of the strains, Bacillus sp. E226, had the highest lipid content at 54.5%. The study also compared the lipid production of these bacteria to other studies on yeasts and fungi, noting that the Bacillus strains had higher lipid content. This study is significant as it highlights the potential of Bacillus sp. strains for lipid production and their applications in biotechnology. [Extracted from the article]

Autofluorescence is frequently observed in animal tissues, interfering with an experimental analysis and leading to inaccurate results. Sudan black B (SBB) is a staining dye widely used in histological studies to eliminate autofluorescence. In this study, our objective was to characterize brain tissue autofluorescence present in three models of acute brain injury, including collagenase-induced intracerebral hemorrhage (ICH), traumatic brain injury (TBI), and middle cerebral artery occlusion, and to establish a simple method to block autofluorescence effectively. Using fluorescence microscopy, we examined autofluorescence in brain sections affected by ICH and TBI. In addition, we optimized a protocol to block autofluorescence with SBB pretreatment and evaluated the reduction in fluorescence intensity. Compared to untreated, pretreatment with SBB reduced brain tissue autofluorescence in the ICH model by 73.68% (FITC), 76.05% (Tx Red), and 71.88% (DAPI), respectively. In the TBI model, the ratio of pretreatment to untreated decreased by 56.85% (FITC), 44.28% (Tx Red), and 46.36% (DAPI), respectively. Furthermore, we tested the applicability of the protocol using immunofluorescence staining or Cyanine-5.5 labeling in the three models. SBB treatment is highly effective and can be applied to immunofluorescence and fluorescence label imaging techniques. SBB pretreatment effectively reduced background fluorescence but did not significantly reduce the specific fluorescence signal and greatly improved the signal-to-noise ratio of fluorescence imaging. In conclusion, the optimized SBB pretreatment protocol blocks brain section autofluorescence of the three acute brain injury models. [ABSTRACT FROM AUTHOR]

The 3D visualization based on tissue clearing technology allows us to have a deeper understanding of the 3D spatial information of deep molecules in the tissue. Tissue clearing and bacterial labeling methods have been used for in situ 3D microbiota imaging, and we have developed a pipeline for 3D visualization of in situ microbiota in human gliomas. Anti‐LPS antibodies are appropriate to label and characterize bacteria in situ within tumors. However, autofluorescence (AF) is common in biological tissues, especially in brain tissues filled with lipofuscin‐like (LF) substances. This natural fluorescent signal is usually considered to be a problem because it affects the 3D visualization of fluorescent signals in bacterial LPS staining. Here, we used Sudan Black B (SBB) to mask the AF of human glioma tissue and explored in detail the optimal quencher concentration, which allows 3D visualization of intratumoral bacteria to reduce AF and maintain the intensity of intratumoral bacteria‐specific LPS fluorescent signals. [ABSTRACT FROM AUTHOR]

A new method for senescent cell detection is described, which is based on lipofuscin labeling with a fluorescent reporter through a biorthogonal strain‐promoted azide‐alkyne cycloaddition. The sensing protocol involves a first step where the interaction of lipofuscin with a Sudan Black B derivative containing an azide moiety (SBB‐N3) is carried out. In the final step, the azide moiety reacts with a fluorophore containing a cyclooctene ring (BODIPY). The efficacy of this two‐step protocol is assessed in senescent melanoma SK‐MEL‐103 cells, senescent triple‐negative breast cancer MDA‐MB‐231 cells and senescent WI‐38 fibroblasts. In all cases, a clear fluorescence pattern was observed in senescent cells, compared to proliferative cells, only when the SBB‐N3‐BODIPY probe was formed. Our results provide an alternative tool for the detection of senescent cells, based on an in situ bio‐orthogonal reaction for lipofuscin labeling. [ABSTRACT FROM AUTHOR]

Abstract Immunofluorescence assay is one of methods to understand the spatial biology by visualizing localization of biomolecules in cells and tissues. Autofluorescence, as a common phenomenon in organisms, is a background signal interfering the immunolocalization assay of schistosome biomolecules, and may lead to misinterpretation of the biomolecular function. However, applicable method for reducing the autofluorescence in Schistosoma remains unclear. In order to find a suitable method for reducing autofluorescence of schistosomes, different chemical reagents, such as Sudan black B (SBB), trypan blue (TB), copper sulfate (CuSO4), Tris-glycine (Gly), and ammonia/ethanol (AE), at different concentrations and treatment time were tested, and SBB and CuSO4 were verified for the effect of blocking autofluorescence in immunofluorescence to localize the target with anti-SjCRT antibody. By comparing the autofluorescence characteristics of different conditions, it was found that SBB, TB and CuSO4 had a certain degree of reducing autofluorescence effect, and the best effect in females was using 50 mM CuSO4 for 6 h and in males was 0.5% SBB for 6 h. Furthermore, we have applied the optimized conditions to the immunofluorescence of SjCRT protein, and the results revealed that the immunofluorescence signal of SjCRT was clearly visible without autofluorescence interference. We present an effective method to reduce autofluorescence in male and female worm of Schistosoma japonicum for immunofluorescence assay, which could be helpful to better understand biomolecular functions. Our method provides an idea for immunofluorescence assay in other flukes with autofluoresence.

Immunofluorescence assay is one of methods to understand the spatial biology by visualizing localization of biomolecules in cells and tissues. Autofluorescence, as a common phenomenon in organisms, is a background signal interfering the immunolocalization assay of schistosome biomolecules, and may lead to misinterpretation of the biomolecular function. However, applicable method for reducing the autofluorescence in Schistosoma remains unclear. In order to find a suitable method for reducing autofluorescence of schistosomes, different chemical reagents, such as Sudan black B (SBB), trypan blue (TB), copper sulfate (CuSO4), Tris-glycine (Gly), and ammonia/ethanol (AE), at different concentrations and treatment time were tested, and SBB and CuSO4 were verified for the effect of blocking autofluorescence in immunofluorescence to localize the target with anti-SjCRT antibody. By comparing the autofluorescence characteristics of different conditions, it was found that SBB, TB and CuSO4 had a certain degree of reducing autofluorescence effect, and the best effect in females was using 50 mM CuSO4 for 6 h and in males was 0.5% SBB for 6 h. Furthermore, we have applied the optimized conditions to the immunofluorescence of SjCRT protein, and the results revealed that the immunofluorescence signal of SjCRT was clearly visible without autofluorescence interference. We present an effective method to reduce autofluorescence in male and female worm of Schistosoma japonicum for immunofluorescence assay, which could be helpful to better understand biomolecular functions. Our method provides an idea for immunofluorescence assay in other flukes with autofluoresence. [ABSTRACT FROM AUTHOR]

Poly-β-hydroxybutyrate (PHB) is the simplest member of polyhydroxyalkanoates (PHAs) that are biological polyesters or biopolymers produced by a wide variety of bacteria as an intracellular storage material of carbon and energy. Compost is one of the richest sources of microorganisms; therefore, an attempt was made to isolate PHB producing bacteria from compost samples. Out of six compost samples, bioslurry showed the highest mesophilic bacterial count of 3.75×109 cfu/g. A total of 48 mesophilic bacteria were isolated by growing samples on nutrient agar medium at pH 7.0 and a temperature of 37°C. All isolates were purified and screened for PHB production using lipophilic stains such as Nile red, Sudan black B, Acridine orange. 16 out of 48 isolates exhibited PHB production ability after screening by plate assay. PHB granule formation was also confirmed by observation under a fluorescent microscope. The number of PHB producer and accumulators in different compost samples were in the order of Bioslurry > Cow dung > Cotton seed > Tobacco dust. Based on morphological, cultural and biochemical characteristics, all isolates were assigned to four genera viz. Bacillus, Micrococcus, Veillonella and Pseudomonas. Batch fermentation in shake flask was carried out using glucose as carbon source. By analyzing photomicrographs of 24-hour old cultures, 7 out of 16 bacterial isolates were found with a good PHB accumulation capacity. These bacteria are being currently studied for biopolymer production using different carbon sources and renewable biomass.

Brain tissue contains autofluorescing elements that potentially impede accurate identification of neurons when visualized with fluorescent microscopy. Age-related accumulation of molecules with autofluorescent properties, such as lipofuscin, can possess spectral profiles that invade the typical emission range of fluorophores commonly utilized in fluorescent microscopy. The traditional method for accounting for this native fluorescence is to apply lipophilic dyes that are able to sequester these unwanted signals. While effective, such dyes can present a range of problems including the obstruction of fluorescent probe emissions. The present study utilizes aged primate midbrain tissue stained for tyrosine hydroxylase and calbindin to investigate an image processing approach for removing autofluorescence utilizing spectral imaging and linear unmixing. This technique is then compared against the traditional, dye-based autofluorescence sequestration method using Sudan Black B (SBB). Spectral imaging and linear unmixing yielded significantly higher cell numbers than SBB treatment. This finding suggests that computational approaches for removing autofluorescence in neural tissue are both viable and preferential to dye-based approaches for estimation of cell body numbers.

Bio-plastic synthesis from renewable and cheap agro-based materials is a sustainable solution for replacing conventionally produced plastic with environmental contamination. The current study was aimed at screening and characterization of Polyhydroxyalkanoates (PHA) producing bacterial isolates, evaluation of their potential and recovery of PHA using the isolates. The PHA compounds were characterized using FT-IR. Based on 16SrRNA sequence analyses the isolates were designated as Bacillus sp. BPPI-14 and Bacillus sp. BPPI-19. The isolates were gram-positive, rod-shaped, endospore former, and citrate test positive. Intracellular PHA granules were observed when these isolates were stained with Sudan black B (SBB) and Nile blue A (NBA) preliminary and specific staining dyes, respectively. Effect of pH, temperature and carbon sources on the PHA production by the isolates BPPI-14 and BPPI-19 was studied. Maximum PHA production was recorded for Glucose (49.46 ± 2.79%) by Bacillus sp. BPPI-14 and followed by molasses (45.86 ± 2.17%) by Bacillus sp. BPPI-19, respectively at 37 °C and pH 7. The obtained PHA polymers were confirmed by preparation of plastic films for both the isolates. Fourier transform infrared spectrum for BPPI-14 and BPPI-19 showed the peak (carboxylic acid group) at 1706–1719.39 cm−1 was a characteristic feature of PHA and corresponds functional group (C=O). [ABSTRACT FROM AUTHOR]

Abstract The use of Sudan black B as coloring agent in foods is forbidden for its toxicology effect on human organs. This work proposes an efficient and sensitive method for food security inspection targeting Sudan black B. Surface-enhanced Raman spectroscopy (SERS) is applied to the analysis of trace Sudan black B. It could be detected at concentrations as low as 0.05 mg/L in standard solutions and 0.1 mg/kg in black rice extracts with the SERS method for measurement. The linear relationship between the intensity and concentration could be used for the quantitative detection of Sudan black B. The relation between dyeing time of black rice stained by Sudan black B solution and SERS intensity was studied which indirectly showed the effectiveness of the extraction method we designed. The results of the quantitative analysis reveal the practicability of using this method to detect Sudan black B in black rice. As a rapid and sensitive detection method, SERS can be extended to detect other food products and has a great application prospect in food safety inspection. Graphical abstract Unlabelled Image Highlights • The Raman spectra of Sudan black B were obtained using SERS in optimal test conditions. • An effective extraction method proposed to obtain black rice extracts. • The dyeing effect of Sudan black on black rice was studied. • The quantitative results were applied to the detection of Sudan black B in dyed black rice. [ABSTRACT FROM AUTHOR]

The combination of advanced mass spectrometry and enrichment-based sample preparation methods has enhanced analytical capabilities in clinical proteomics. In this chapter, we describe a method of proteome analysis to identify Borrelia-derived peptides in urine that includes a sample affinity enrichment method coupled with liquid chromatography tandem mass spectrometry analysis and a bioinformatic peptide authentication algorithm., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

The present work aims to demonstrate the stages of fabrication and use of a simple device to avoid the formation or fixation of precipitates from Sudan Black B solution on tissues. The device consists of four coverslip fragments attached to a histology slide, which serve as points of support for the histological slide under analysis. To work properly, the histology slide with the sections should be placed with the sections facing downwards the device. A small space between the device and the histology slide is thereby created by the height of the coverslip fragments. When Sudan Black B is applied, the solution is maintained within the edges of the device and evaporation is minimized by the small space, thereby reducing the consequent formation of precipitates. Furthermore, by placing the sections facing downward the device, any sporadically formed precipitates are prevented from settling on and fixing to the sectioned tissues or organs. By avoiding the formation of precipitates, plant cells, tissues and organs can be better observed, diagnosed and photomicrographically recorded.

The autofluorescence of animal tissues complicates the results obtained using fluorescence microscopy. Many techniques have been used to reduce autofluorescence; however, all these techniques have the disadvantage of reducing the intensity of immunofluorescence staining. We observed the features of autofluorescence in formalin-fixed paraffin-embedded (FFPE) vascularized liver and kidney sections and assessed the effects of an intravascular treatment with erythrocyte lysis solution (ELS) before a routine perfusion with normal saline (NS) and Sudan Black B (SBB) treatment after antigen retrieval on reducing autofluorescence reduction and the visualization of antigens to establish an optimal method for reducing autofluorescence. Erythrocytes exhibited bright autofluorescence in FFPE liver and kidney sections, which altered the results of actin and destrin immunofluorescence staining. The SBB treatment significantly reduced background autofluorescence and exerted a moderate effect on reducing the autofluorescence of erythrocytes, and the intravascular ELS treatment eliminated erythrocyte autofluorescence in FFPE liver and kidney sections. A combined treatment with ELS and SBB further reduced autofluorescence but did not decrease actin and destrin immunofluorescence staining in double-labeled FFPE liver and kidney sections. In conclusion, the application of an intravascular ELS treatment before the NS perfusion combined with an SBB treatment after antigen retrieval is a simple and efficient strategy for reducing autofluorescence in FFPE vascularized tissues and can be broadly used in fluorescence microscopy analyses. [ABSTRACT FROM AUTHOR]

Highlights • We described the cytochemical staining features of Chinese alligator blood cells. • Established the cytochemical patterns of different types of blood cells. • The cytochemical patterns shared certain commonality with those of other reptiles. • Some notable species specificity was also found. Abstract The Chinese alligator (Alligator sinensis) is an endemic rare crocodilian species in China. In this study, we investigated the cytochemical patterns of peripheral blood cells in Chinese alligators for the first time by a range of cytochemical staining techniques including periodic acid-Schiff(PAS), sudan black B(SBB), peroxidase(POX), alkaline phosphatase(AKP), acid phosphatase(ACP), chloroacetic acid AS-D naphthol esterase(AS-D) and α-naphthol acetate esterase(α-NAE) staining. Erythrocytes were positive for PAS, and negative for all the other staining; heterophils were strongly positive for SBB, POX, ACP, AKP, AS-D and α-NAE, while weakly positive for PAS staining; eosinophils were strongly positive for PAS, POX, AKP, ACP and AS-D, and weakly positive for SBB and α-NAE staining; basophils were strongly positive for PAS, positive for POX, ACP, AKP and α-NAE, and weakly positive for AS-D, while negative for SBB staining; monocytes were weakly positive for PAS, ACP, AKP and α-NAE, while negative for SBB, POX and AS-D staining; lymphocytes were weakly positive for PAS and α-NAE, negative for all the other staining; thrombocytes were weakly positive for PAS, and negative for all the other staining. Our results add up knowledge about Chinese alligator blood cells. [ABSTRACT FROM AUTHOR]

The presence of intracellular polyhydroxyalkanoates (PHAs) is usually studied using Sudan black dye solution (SB). In a previous work it was shown that the PHA could be directly quantified using the absorbance of SB fixed by PHA granules in wet cell samples. In the present paper, the optimum SB amount and the optimum conditions to be used for SB assays were determined following an experimental design by hybrid response surface methodology and desirability-function. In addition, a new methodology was developed in which it is shown that the amount of SB fixed by PHA granules can also be determined indirectly through the absorbance of the supernatant obtained from the stained cell samples. This alternative methodology allows a faster determination of the PHA content (involving 23 and 42 min for indirect and direct determinations, respectively), and can be undertaken by means of basic laboratory equipment and reagents. The correlation between PHA content in wet cell samples and the spectra of the SB stained supernatant was determined by means of multivariate and linear regression analysis. The best calibration adjustment ( R 2  = 0.91, RSE: 1.56%), and the good PHA prediction obtained (RSE = 1.81%), shows that the proposed methodology constitutes a reasonably precise way for PHA content determination. Thus, this methodology could anticipate the probable results of the above mentioned direct PHA determination. Compared with the most used techniques described in the scientific literature, the combined implementation of these two methodologies seems to be one of the most economical and environmentally friendly, suitable for rapid monitoring of the intracellular PHA content. [ABSTRACT FROM AUTHOR]

Immunofluorescence (IF) staining of paraffin-embedded tissues is a frequently used method to answer research questions or even detect the abundance of a certain protein for diagnostic use. However, the signal originating from specific antibody-staining might be distorted by autofluorescence (AF) of the assessed tissue. Although the AF phenomenon is well known, its presence is often neglected by insufficient staining controls. In this study, we describe the existence of cellular AF in paraffin-embedded healthy and inflamed human and murine colonic tissues and present ways to reduce AF. The AF signal is detectable at emission spectra from 425 nm–738 nm, upon excitation from 403.6–638.7 nm and appears more pronounced in inflamed tissues. Most signals are located subepithelially in the tissue and in blood vessels. Previous studies have shown that the AF signals are caused by lipofuscin, which accumulates in lamina propria immune cells. In murine small intestine AF signals are present in granules in the Paneth cell zone. For alleviation of the AF signal, sudan black b (SBB) or copper sulfate was used. Incubation of the tissue slices with either one of the substances reduced AF. In conclusion, AF appears as an intrinsic biomarker for colonic inflammation. The dominant existence of AF in immune cells of IBD tissue elucidates the importance of negative controls and the limitation of IF staining for potential diagnostic purposes. [ABSTRACT FROM AUTHOR]

Non-specific fluorescence from demineralized enamel matrix can significantly compromise the immunofluorescence studies and lead to false positives. Our goal was to assess degrees of non-specific binding under different conditions and try to optimize procedures for immunofluorescence studies of forming enamel. Firstly, we compared two methods for background fluorescence elimination, i.e., sodium borohydride and Sudan Black B treatments. The results demonstrated that Sudan Black B is far superior to sodium borohydride in reducing the background fluorescence in dental tissues. We also studied the extent of non-specific binding of normal sera and purified polyclonal immunoglobulins (IgG) from five mammalian species, guinea pig, rat, rabbit, goat, and sheep, over a broad range of dilutions. For all sera tested fluorescence signals increased exponentially from 1:1000 to 1:100. Interestingly, the non-specific binding of sera from rodent species was below that of positive control in the whole range of dilutions. In contrast, incubation with sera from 3 non-rodent species produced much higher signals which surpassed the positive control signal at 1:250~1:500 dilution range. Most of the IgGs didn't show significant non-specific binding within 0.25–5 μg/ml range, except rabbit IgG which demonstrated extremely high affinity to the enamel matrix even at concentrations as low as 1 μg/ml. Further, studies confirmed that Fab fragments of purified normal rabbit IgG, not conserved Fc fragments, were involved in the interactions. Our observations suggest this high affinity is associated with the antigen binding sites of rabbit IgG. We anticipate that our results will help enamel researchers to optimize and standardize their immunochemical procedures.

Significant autofluorescence (AF) of renal tissue is one of the major causes restricting the use of immunofluorescent staining. This study aimed at controlling renal tissue AF and testing an effective method for optimizing specific signals. In the present study, we observed emergence of strong AF in all renal cells under different fluorescent channels. Significant concentration-dependent reduction in AF of kidney tissue was observed with the use of sodium borohydride (NaBH4) and Sudan black B (SBB) alone (p < 0.05). Under maximum effective concentration, semi-quantitative analysis revealed that inhibitory effect of SBB on AF was superior to that of NaBH4 (P < 0.01). When the two chemicals were combined, we observed that background can be reduced, and specific staining can be optimized at optimum concentration. Intensity of renal tissue was examined by confocal λ scanning, which showed that peaks were located at the range of approximately 480 − 590 nm and similar to those of flavin and lipofuscin. These results indicated that combined use of NaBH4 and SBB, when targeted at different sources of AF in renal tissue, is the most effective means of reducing background and preserving specificity of fluorescent labels. In addition, this method does not interfere with various steps of immunofluorescence experiments. [ABSTRACT FROM AUTHOR]

Poly-β-hydroxybutyrate (PHB) is the simplest member of polyhydroxyalkanoates (PHAs) that are biological polyesters or biopolymers produced by a wide variety of bacteria as an intracellular storage material of carbon and energy. Compost is one of the richest sources of microorganisms; therefore, an attempt was made to isolate PHB producing bacteria from compost samples. Out of six compost samples, bioslurry showed the highest mesophilic bacterial count of 3.75x109 cfu/g. A total of 48 mesophilic bacteria were isolated by growing samples on nutrient agar medium at pH 7.0 and a temperature of 37°C. All isolates were purified and screened for PHB production using lipophilic stains such as Nile red, Sudan black B, Acridine orange. 16 out of 48 isolates exhibited PHB production ability after screening by plate assay. PHB granule formation was also confirmed by observation under a fluorescent microscope. The number of PHB producer and accumulators in different compost samples were in the order of Bioslurry > Cow dung > Cotton seed > Tobacco dust. Based on morphological, cultural and biochemical characteristics, all isolates were assigned to four genera viz. Bacillus, Micrococcus, Veillonella and Pseudomonas. Batch fermentation in shake flask was carried out using glucose as carbon source. By analyzing photomicrographs of 24-hour old cultures, 7 out of 16 bacterial isolates were found with a good PHB accumulation capacity. These bacteria are being currently studied for biopolymer production using different carbon sources and renewable biomass. [ABSTRACT FROM AUTHOR]

Colored waterborne polyurethanes have been widely used in paintings, leathers, textiles, and coatings. Here, a series of black waterborne polyurethanes (WPUs) with different ratios of black dye, Sudan Black B (SDB), were prepared by step-growth polymerization. WPU emulsions as obtained exhibit low particle sizes and remarkable storage stability at the same time. At different dye loadings, essential structural, statistical and thermal properties are characterized. FTIR (fourier transform infrared) spectra indicate that SDB is covalently linked into waterborne polyurethane chains. All of the WPUs with covalently linked SDB show better color fastness and resistance of thermal migration than those with SDB mixed physically. Besides, WPUs incorporated SDB covalently with different polymeric diols, polytetramethylene ether glycol (PTMG), polypropylene glycol (PPG), poly-1, 4-butylene adipate glycol (PBA) and polycaprolactone glycol (PCL), were prepared to obtain different properties to cater to a variety of practical demands. By a spraying method, the black WPUs can be directly used as metal coatings without complex dyeing process by simply mixing coating additive and other waterborne resins, which exhibit excellent coating performance. [ABSTRACT FROM AUTHOR]

Non-specific fluorescence from demineralized enamel matrix can significantly compromise the immunofluorescence studies and lead to false positives. Our goal was to assess degrees of non-specific binding under different conditions and try to optimize procedures for immunofluorescence studies of forming enamel. Firstly, we compared two methods for background fluorescence elimination, i.e., sodium borohydride and Sudan Black B treatments. The results demonstrated that Sudan Black B is far superior to sodium borohydride in reducing the background fluorescence in dental tissues. We also studied the extent of non-specific binding of normal sera and purified polyclonal immunoglobulins (IgG) from five mammalian species, guinea pig, rat, rabbit, goat, and sheep, over a broad range of dilutions. For all sera tested fluorescence signals increased exponentially from 1:1000 to 1:100. Interestingly, the non-specific binding of sera from rodent species was below that of positive control in the whole range of dilutions. In contrast, incubation with sera from 3 non-rodent species produced much higher signals which surpassed the positive control signal at 1:250~1:500 dilution range. Most of the IgGs didn't show significant non-specific binding within 0.25-5µg/ml range, except rabbit IgG which demonstrated extremely high affinity to the enamel matrix even at concentrations as low as 1µg/ml. Further, studies confirmed that Fab fragments of purified normal rabbit IgG, not conserved Fc fragments, were involved in the interactions. Our observations suggest this high affinity is associated with the antigen binding sites of rabbit IgG. We anticipate that our results will help enamel researchers to optimize and standardize their immunochemical procedures. [ABSTRACT FROM AUTHOR]

Aims The search for novel drugs that enhance myelin repair in entities such as multiple sclerosis has top priority in neurological research, not least because remyelination can hinder further neurodegeneration in neuro-inflammatory conditions. Recently, several new compounds with the potential to boost remyelination have been identified using high-throughput in vitro screening methods. However, assessing their potential to enhance remyelination in vivo using plastic embedded semi-thin sections or electron microscopy, even though being the gold standard for assessing remyelination, is toxic, extremely time-consuming and expensive. Methods We screened available myelin dyes for a staining candidate which offers a faster and easier alternative to visualize remyelination in cryo-sections. Results We identified sudan black as a candidate with excellent myelin resolution and we show that our adapted sudan black staining can demonstrate myelin repair in rodent spinal cord cryosections as reliable as in semithin sections, but much faster, easier, less toxic and less expensive. Besides that, it can resolve the small myelinated axons in the corpus callosum. The staining can yet readily be combined with immunostainings which can be challenging in semithin sections. We validated the method in human spinal cord tissue as well as in experimental demyelination of the rat spinal cord by a lysolecithin time course experiment. As proof-of-principle, we demonstrate that sudan black is able to reliably detect the remyelination enhancing properties of benztropine. Conclusion Our adapted sudan black staining can be used to rapidly and non-toxically screen for remyelinating therapies in demyelinating diseases. [ABSTRACT FROM AUTHOR]

Few studies considered the anatomy of the nerve plexuses and musculature associated with them in ectothermic sauropsids. Based on differentiated Sudan Black B staining and conventional dissections, we describe the neuroanatomy of the brachial plexus, its main associated nerves, and muscles. For that, representatives of the genera Diplolaemus, Liolaemus, Phymaturus, and Tropidurus were selected. Based on this, potentially useful characters for phylogenetic analysis were described. Our results show that the brachial plexus can be formed by four, five, or six nerve branches. The brachial flexor trunk, circumflex, interosseous, median, radial, subscapulocoracoid, supracoracoid, and ulnar nerves were identified. Regarding the muscles innervated by the main nerves, the following muscles were identified: biceps brachii, deltoideus scapularis, latissimus dorsi, levator scapulae, pectoralis, serratus thoracis, trapezius, triceps longus caudalis, and triceps longus lateralis. Phylogenetic analyzes revealed 31 potential synapomorphies. There exists evidence that neuroanatomy studies in a phylogenetic context could provide useful information helping to elucidate the relationships between taxonomic groups., (© 2023 Wiley Periodicals LLC.)

Cellular senescence contributes to organismal development, aging, and diverse pathologies, yet available assays to detect senescent cells remain unsatisfactory. Here, we designed and synthesized a lipophilic, biotin-linked Sudan Black B ( SBB) analogue suitable for sensitive and specific, antibody-enhanced detection of lipofuscin-containing senescent cells in any biological material. This new hybrid histo-/immunochemical method is easy to perform, reliable, and universally applicable to assess senescence in biomedicine, from cancer research to gerontology. [ABSTRACT FROM AUTHOR]

Investigations have been made to optimize various factors including pH, temperature, and substrate for enhanced polyhydroxybutyrate (PHB) production in Botryococcus braunii which serves as a pioneer for production of bioplastic (PHB). Polyhydroxybutyrate is a natural, decomposable polymers accumulated by the microorganism under different nutritional condition. Strain selection was done by staining method using Sudan black and Nile red dye. Using response surface methodology (RSM), three level- three variables Box Behnken design (BBD), the best potential combination of pH (4–11), temperature (30–50 °C) and sewage waste water as substrate fed at different concentrations at 20%–100% for maximum PHB production was investigated. Maximum yield (247 ± 0.42 mg/L) of PHB dry weight was achieved from the 60% concentration of sewage waste water as a growth medium at pH 7.5 at 40 °C. It was well in close agreement with the value predicted by RSM model yield (246 ±  0.32 mg/L). Thus the study shows the production of PHB by B. braunii along with the basic characterization of PHB by using FTIR and TEM analysis. These preliminary studies indicated that PHB can also be produced by B. braunii utilizing waste water. There is no report on the optimization of PHB production in this microalgae have been documented. [ABSTRACT FROM AUTHOR]

Schizochytrium sp. is a hopeful docosahexaenoic acid (DHA) producing candidate due to its rapid growth rate and high DHA proportion in total lipid content. In this study, low-energy ion implantation was applied to Schizochytrium sp. to induce high DHA-producing mutants. Screening these mutants by Sudan black B staining, a mutant strain S1 which showed a 61% improvement in DHA production than that of the parent strain was successfully selected. Subsequently, parameters of DHA production of mutant strain S1 were optimized in a 500-mL Erlenmeyer flask. Under the optimum fermentation conditions, the production of DHA and the percentage of DHA in total lipid of mutant strain S1 were 6.52 g/L and 46.2%, respectively. This study provides an effective breeding strategy for improved DHA production of Schizochytrium sp. through combination of the novel mutagenesis technology, the effective screening method and fermentation optimization. [ABSTRACT FROM AUTHOR]

In this research, the removal of Sudan black B (SBB) by cadmium hydroxide nanowires loaded on activated carbon is described. After optimizing the variables involved, Langmuir, Freundlich, Tempkin, and Dubinin–Radushkevich models were applied to fit the experimental data. The adsorbent correlation coefficient and error analysis indicated the applicability of Langmuir model for the interpretation of equilibrium data. Different kinetic models were applied to analyze the time evolution of removal data. It was found that low quantity of adsorbent (<0.03 g) is capable of removal of large amount of SBB in reasonably short time (<40 min). The adsorption process was found to be described by both pseudo–second-order kinetics and interparticle diffusion mechanism. The effects of variables such as pH, amount of adsorbent, and contact time on batch adsorption process were investigated and optimized. [ABSTRACT FROM AUTHOR]

Aims High levels of autofluorescence in tissue samples can entirely mask specific labellings with fluorophores and thus impair immunofluorescence histochemistry. In pancreatic tissue samples we observed autofluorescence as a common problem often mediated by the fixation and processing procedure. Methods and results Using epifluorescence microscopy, we analysed the intensity and spatial distribution of autofluorescence in formalin-fixed, paraffin-embedded human pancreatic tissues and developed an efficient quenching method to reduce the unwanted light emission. The optimized quenching protocol using Sudan black B reduced the unequally distributed tissue autofluorescence to a low and intensity-equalized background level. Quantitative image analysis demonstrated autofluorescence suppression by 65-95%, depending on the selected fluorescence filter setups. The procedure did not affect specific immunofluorescence labelling or tissue integrity. As a clear result of Sudan black B treatment, a tremendous improvement of the signal-to-noise ratio was achieved, allowing a reliable detection and quantification of specific fluorescent labels. Other tissue treatment methods, such as cupric sulphate, toluidine blue and ultraviolet irradiation, or combinations of these with Sudan black B, were not as efficient. Conclusions The easy-to-perform Sudan black B technique improves dramatically qualitative and quantitative fluorescence analysis of critical pancreatic tissue sections and rescues even overfixed tissues for immunofluorescence application. [ABSTRACT FROM AUTHOR]

Histochemical techniques today allow you to select areas of tissue and generate reliable information on the distribution of energy reserves in bivalve molluscs during their life cycle. The main objective of this study was to describe and relate the gametogenic cycle with the availability of energy reserves and the environmental parameters. For this, we sampled and examined the gonads and digestive glands (DG) of 15 individuals collected monthly during April 2012 and February 2013. We processed and analyzed the samples by standard histological and histochemical light microscopy techniques. Our results showed that for the gametogenic cycle, the monthly proportion of mature organisms was higher for males, between August (40%) and November (53%), while the females tend to have a shorter synchronized cycle and release of gametes in September (67%) and October (60%). The intense spawning periods in both sexes was the same (October to January). Between the periods April-August 2012 and January-February 2013, we observed the highest values of IGl and glucide index (instead, a decrease was observed in September, reaching minimum values during the period October-December). Besides, the maximum values of IL, lipid index, were observed in April-2012 and February-2013, with an intermediate value in August-2013. The results indicated that the reserves of the GD have a pattern of mobilization inversely related to the proliferation of gametes in both sexes; this was directly linked to the availability of nutrients such as chlorophyll a and the organic seston. [ABSTRACT FROM AUTHOR]

Natural polymers are extensively utilized as scaffold materials in tissue engineering and 3D disease modeling due to their general features of cytocompatibility, biodegradability, and ability to mimic the architecture and mechanical properties of the native tissue. A major limitation of many polymeric scaffolds is their autofluorescence under common imaging methods. This autofluorescence, a particular challenge with silk fibroin materials, can interfere with the visualization of fluorescently labeled cells and proteins grown on or in these scaffolds, limiting the assessment of outcomes. Here, Sudan Black B (SBB) was successfully used prefixation prior to cell seeding, in various silk matrices and 3D model systems to quench silk autofluorescence for live cell imaging. SBB was also trialed postfixation in silk hydrogels. We validated that multiple silk scaffolds pretreated with SBB (hexafluoro-2-propanol-silk scaffolds, salt-leached sponges, gel-spun catheters, and sponge-gel composite scaffolds) cultured with fibroblasts, adipose tissue, neural cells, and myoblasts demonstrated improved image resolution when compared to the nonpretreated scaffolds, while also maintaining normal cell behavior (attachment, growth, proliferation, differentiation). SBB pretreatment of silk scaffolds is an option for scaffold systems that require autofluorescence suppression.

Alveolar epithelial type II (AE2) cells produce, store and secrete pulmonary surfactant and serve as progenitor cells for the alveolar epithelium. They are thus an interesting target in wide fields of pulmonary research. Stereological methods allow their quantification based on measurements on histological sections. A proper AE2 cell quantification, however, requires a method of tissue processing that results in little tissue shrinkage during processing. It was recently shown that a primary fixation with a mixture of glutaraldehyde and formaldehyde, postfixation with osmium tetroxide and uranyl acetate and embedding in glycol methacrylate fulfills this requirement. However, a proper quantification, furthermore, requires a secure identification of the cells under the microscope. Classical approaches using routine stainings, high magnifications and systematic uniform random sampling can result in a tedious counting procedure. In this article we show that Sudan Black B and Sudan III staining in combination with the previously described “low shrinkage method” of tissue processing result in good staining of lamellar bodies of AE2 cells (their storing organelles of surfactant) and thus provide a good signal of AE2 cells, which allows their easy and secure identification even at rather low magnifications. We further show that this signal enables automated detection of AE2 cells by image analysis, which should make this method a suitable staining method for the recently developed and more efficient proportionator sampling. [ABSTRACT FROM AUTHOR]