Analysis of serum purines and pyrimidines by isotachophoresis

Purine and pyrimidine metabolism receive attention from a rapidly growing number of workers in the field of inborn errors (1), hematology (2), immunology (3) and oncology (4,5). The availability of metabolite profiles of body fluids and cell contents might attribute to a better understanding of mechanisms underlying metabolic disturbances. This enables a more direct approach for both diagnostic and experimental purposes. For identification of purines and pyrimidines thin-layer high voltage electrophoresis and chromatography can be used (6). A more rapid technique involves high performance liquid chromatography (HPLC) and is widely used at present (7,8). An alternative to HPLC for a screening of metabolite profiles might be isotachophoresis (9). This technique has recently been introduced for the separation and identification of muscle nucleotides (10) and urinary purines and pyrimidines (11). An advantage of isotachophoresis as compared to HPLC is its flexibility: buffers can be changed rapidly, no columns need to be equilibrated. In this paper two systems are presented for the separation of a number of purines and pyrimidines in serum: one low-pH system (pH 3.9) for nucleotides and one high-pH system (pH 7.75) for bases and nucleosides