Continuous-flow enzymic determination of creatine in urine.
A new enzymic method is described for the determination of creatine in urine by continuous-flow analysis. The measurement is accomplished by transforming creatine to formaldehyde in reactions catalyzed by creatinase (creatine amidinohydrolase) and sarcosine dehydrogenase. The formaldehyde is reacted with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to form a purple product, which is measured colorimetrically. The method gives a linear standard curve for creatine concentrations up to 100 mg/L. Precision and analytical recovery are excellent, and results correlate well with those by the more-difficult Folin method, which currently is most often used for this analysis.
D001322:Autoanalysis; D003401:Creatine / Q000652:urine*; D006801:Humans; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D011549:Pseudomonas / Q000201:enzymology; D012521:Sarcosine / Q000378:metabolism; D050892:Sarcosine Dehydrogenase; D013053:Spectrophotometry / Q000379:methods; D014512:Ureohydrolases / Q000378:metabolism
D010089:Oxidoreductases, N-Demethylating; C494395:SARDH protein, human; D050892:Sarcosine Dehydrogenase; D014512:Ureohydrolases; C019944:creatinase; D003401:Creatine; D012521:Sarcosine