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A method for the determination of selected amino acids in culture medium using HPLC with fluorescence detection is described. Twenty hours after intra-cytoplasmic sperm injection, one randomly selected zygote was transferred to the culture medium. After incubation (72 h after fertilization), the culture medium in which the embryo was incubated and blank medium was immediately stored at -80°C. Filtered medium samples were derivatized with ortho-phthalaldehyde (naphthalene-2,3-dicarboxaldehyde), forming highly fluorescent amino acids derivatives. Reverse-phase columns (LichroCART, Purospher STAR RP 18e or Ascentis Express C 18 ) were used for the separation. The derivatives were analyzed by gradient elution with a mobile phase containing ethanol and sodium dihydrogen phosphate. The analytical performance of this method is satisfactory for all amino acids; the intra-assay coefficients of variation were <10% and quantitative recoveries were between 95.5 and 104.4%. Changes in the levels of selected amino acids before and after human embryo cultivation were observed. After embryo incubation, the levels of all amino acids in the medium were increased, apart from aspartate and asparagine. After the cultivation of some embryos, amino acids which were not part of the medium were detected. Low amino acids turnover was observed in some embryos., (Copyright © 2016 John Wiley & Sons, Ltd.)

A method is described for the determination of fatty acids in dried sweat spot and plasma samples using gas chromatography with flame ionization detection. Plasma and dried sweat spot samples were obtained from a group of blood donors. The sweat was collected from each volunteer during exercise. Sweat was spotted onto collection paper containing butylated hydroxytoluene. Fatty acids were derivatized with acetyl chloride in methanol to form methyl esters of fatty acids. The fatty acids in dried sweat spot samples treated with butylated hydroxytoluene and stored at -20°C were stable for 3 months. Our results indicate that sweat contains, among fatty acids with short chain, also fatty acids with long chain and unsaturated fatty acids. Linear relationships between percentage content of selected fatty acids in dried sweat spot and plasma were observed., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Despite the increasing success of infertility treatment methods of assisted reproduction, it still remains a problem how to select the best embryo that has the potential for further development and implantation. At the present time, embryo selection is based especially on morphological criteria. This approach is subjective; therefore there is a trend to find another more objective and robust method for embryo selection. Embryo metabolism can be used as an indicator of viability. This non-invasive method allows observing changes in the levels of different metabolites in culture medium before and after incubation of the only one embryo. The most mentioned substances are carbohydrates and amino acids as important components of culture medium. Carbohydrates serve predominantly as energy sources, whereas amino acids are precursors of protein and nucleotides, antioxidants, osmolytes, pH regulators etc. Several methods have been proposed for evaluating of embryo metabolic profile of embryo. There are many hypotheses for embryo selection according its metabolic profile.