<P> The Jaffe reaction is a colorimetric method used in clinical chemistry to determine creatinine levels in blood and urine . In 1886 , Max Jaffe ( 1841 -- 1911 ) wrote about its basic principles in the paper Über den Niederschlag , welchen Pikrinsäure in normalem Harn erzeugt und über eine neue Reaction des Kreatinins in which he described the properties of creatinine and picric acid in an alkaline solution . The color change that occurred was directly proportional to the concentration of creatinine , however he also noted that several other organic compounds induced similar reactions . In the early 20th century , Otto Folin adapted Jaffe 's research into a clinical procedure . The Jaffe reaction , despite its nonspecificity for creatinine , is still widely employed as the method of choice for creatinine testing due to its speed , adaptability in automated analysis , and cost - effectiveness , and is the oldest methodology continued to be used in the medical laboratory . It is this nonspecificity that has motivated the development of new reference methods for creatinine analysis into the 21st century . </P>
the jaffee reaction is the basis for methods involving the quantitation of
creatinine levels in blood and urine