Micromethod for the quantitative determination of leucine from biological experimental material using a dansylation technic]

A method is described allowing quantitative determination of leucine from biological material up to 1 - 10(-11) M by means of dansylation of amino acids and their thin-layer chromatographic separation on polyamide microfoils. By selecting [14C]-U-L-leucine as an 'internal' standard, which is added to the tissue during the homogenization procedure, it is possible to correct for data scattering related to variations of the conversion rate or the yield of the dansylation reaction, and to losses in the different steps of thin-layer chromatography that are difficult to standardize.     

Micromethod for the quantitative determination of succinic acid in the fermentation media

Summary A rapid and accurate method is described for the determination of succinic acid allowing direct application of the fermentation broth filtrate to TLC plate. Subsequent chromatographic separation on silica gel thin-layer and detection of succinic acid by a copper salt reagent, permits quantitative densitometric evaluation of succinic acid in the concentration range from 10 to 40 g. The quantitative analyses are reproducible and the assay has a coefficient of variation of 3.2%.     

Micromethod of ultracentrifugation in cesium chloride]

The micromethod of ultracentrifugation in cesium chloride is described. Band destributions have been analysed by the direct scanning of microtubes with the differential doublewave micro-spectrophotometer at 260 nm. The 10(-8)-10(-9) g of DNA or ribosomes are enough for one analysis, tube volume is 2 mul. The method described permits the simultaneous centrifugation of several probe scores. The error of the beyoant density determination is 0.001 g/sm3 relatively internal standard. DNA's from 5 types of Acetabularia were analysed by the developed technique.     

Micromethod for Serogrouping Escherichia coli

A micromethod for serogrouping strains of Escherichia coli is described. The method is accurate, rapid, and economical in terms of time and reagents utilized to perform the test.