An artefact in lactate dehydrogenase isoenzyme patterns, assayed by fluorescence, occurring in the serum of patients with end-stage renal disease requiring maintenance haemodialysis.

In patients with end-stage renal disease requiring maintenance haemodialysis we have observed that serum albumin becomes fluorescent (excitation 356 nm, emission above 405 nm). This fluorescence is detected in the fluorescent assay of lactate dehydrogenase (LDH) isoenzymes on thin-layer agarose creating the impression of an additional LDH isoenzyme anodal to LDH1. This artefact disappears, or is much reduced, following successful donor kidney transplantation. It is not seen in any other pathological condition. This phenomenon can readily be detected by means of "blank" assays on the agarose plates after specimen application and after electrophoresis of the specimen without the substrate overlay.