Search

High-throughput screening platforms are fundamental for the rapid and efficient processing of large amounts of experimental data. Parallelization and miniaturization of experiments are important for improving their cost-effectiveness. The development of miniaturized high-throughput screening platforms is essential in the fields of biotechnology, medicine, and pharmacology. Currently, most laboratories use 96- or 384-well microtiter plates for screening; however, they have disadvantages, such as high reagent and cell consumption, low throughput, and inability to avoid cross-contamination, which need to be further optimized. Droplet microarrays, as novel screening platforms, can effectively avoid these shortcomings. Here, the preparation method of the droplet microarray, method of adding compounds in parallel, and means to read the results are briefly described. Next, the latest research on droplet microarray platforms in biomedicine is presented, including their application in high-throughput culture, cell screening, high-throughput nucleic acid screening, drug development, and individualized medicine. Finally, the challenges and future trends in droplet microarray technology are summarized. [ABSTRACT FROM AUTHOR]

A novel colorimetric aptasensor has been developed for highly sensitive tetracycline (TC) detection based on the peroxidase-like activity of Fe3O4@Cu nanoparticles and "sandwich" oligonucleotide hybridization. The Fe3O4@Cu nanoparticles with high peroxidase-like activity were successfully synthesized under mild conditions. Then, a "sandwich" oligonucleotide hybridization probe (a short amino-modified complementary sequence of a portion of the TC aptamer (cDNA1), TC aptamers, and a long complementary to 5′ terminal TC aptamer sequence (cDNA2)) was created in 96-wells plates via DNA hybridization in the absence of TC from the detection system. The unique "sandwich" oligonucleotide hybridization probe adsorbed large numbers of Fe3O4@Cu nanozymes while further enhancing its peroxidase-like activity. Based on the 3,3′,5,5′-tetramethylbenzidine (TMB)-hydrogen peroxide (H2O2) reporting system, the blue color of the solution decreased linearly with the increase of TC concentration, ranging from 10−3 to 103 μg/L with an ultralow limit of detection (LOD) of 0.91 ng/L (2 pM). The proposed method was successfully applied to detect TC in spiked milk samples, with recoveries of 81.8 to 112%, demonstrating the excellent potential for highly sensitive TC detection in milk. [ABSTRACT FROM AUTHOR]

The authors describe a fluorescence polarization (FP) based strategy for HIV detection. The assay is based on T7 exonuclease assisted quadratic recycling amplification using graphene oxide (GO) as an amplifier of FP. The effect is caused by the finding that the binding forces between GO and ssDNA are much stronger than those between GO and dsDNA. The two probes, P1 and dye labeled P2, resist digestion by T7 exonuclease (T7exo) due to the 5′-termini protrusion. The hairpin probes are absorbed on the surface of GO without the target DNA. While the presence of the target DNA leads to two independent and simultaneous recycling processes with the assistance of T7exo. Due to this quadratic amplification, a large quantity of ssDNA will be absorbed onto the surface of GO, and this will cause a strong enhancement of FP. This polarization assay was applied to design a method for the determination of HIV DNA which displays a detection limit of 9.12 pmol·L. It is highly selective and can be performed in homogeneous solutions. The cascade amplification strategy is not limited to this particular DNA but is perceived to provide a universal platform for sensitive determination of a wide spectrum of DNA target analytes. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]