[Influence of storing conditions on the amino acid concentration in human serum (author's transl)].

Whole blood, serum and deproteinized serum were stored at room temperature up to 24 h and at - 30 degrees C up to one month. The amino acid content was then determined with an automatic amino acid analyser. When whole blood is left at room temperature the concentration of citrulline, alpha-aminobutyric acid, cysteine and tryptophan remains unchanged, whereas the other amino acids show a remarkable increase or decrease. In serum stored for 24 h at room temperature, only the concentrations of aspartic and glutamic acid, serine, cysteine and phenylalanine were altered. With the exception of aspartic and glutamic acid it was possible to leave deproteinized serum up to 24 h at room temperature and up to one month at - 30 degrees C without observing a change in the concentration of the other amino acids. No change occurred, when serum was stored at - 30 degrees C for 24 h.