[Delta-Aminolevulinic acid in urine (screening method)].

Various methods for determining urinary delta-aminolevulinic acid (ALA) have been devised by many investigators since 1956. This paper introduces a history of the methodology in the determination of urinary ALA and application of some methods. These methods can be divided into two groups; one group consists of colorimetric methods based on the color reaction of ALA-pyrrole with Ehrlich's reagent, and the other group consists of fluorometric methods, based on the fluorescence derivatization of ALA and its separation by HPLC. Colorimetric methods are convenient and inexpensive, while these are less specific. On the other hand, the fluorometric HPLC methods are highly sensitive and specific, while these are expensive because of the high cost of the instruments.