The accuracy of creatinine methods based on the Jaffé reaction: a questionable matter

The determination of creatinine in serum based on the Jaffé reaction was evaluated with four current analysers. In particular, the comparability of results was determined also with survey specimens. Recalibration of 3 out of 4 modifications was necessary, based on the results of patient samples as verified with a HPLC-method. One of the methods proved to give an unacceptable scatter for the results in the lower range (30-150 mumol/l). A limited interference study (haemoglobin, lipids, bilirubin and acetone) and a method assessment with quality control sera supported the conclusion that the overall accuracy of creatinine methods based on the Jaffé reaction is questionable.