The determination of amino acids in 0.1 ml. of blood plasma.

A method has been developed for the determination of the following amino acids in 0.1 ml. of blood plasma: alanine, arginine, glutamine, glycine, lysine, serine, taurine, threonine, and valine. A micro Sephadex C-25 column was used to separate the plasma proteins from the amino acids. The amino acid fraction, which is collected in 1 ml. of eluate, is then desalted in an electrolytic desalter, and lyophilized. The residue is dissolved in 0.2 ml. 0.1N HCI, and 50 p.l. is applied to paper for 2-dimensional chromatography. The estimation of the amino acids is carried out by means of a photoelectric densitometer. The method incorporates a procedure for eliminating variations in paper density. The results obtained are in good agreement with those obtained by ionexchange procedures.