Description
The Creatinine Microplate Assay is a colorimetric assay for the quantitative analysis of creatinine levels in urine. Urinary creatinine reacts with picric acid under alkaline conditions to produce an orange color, which can be quantified by absorption spectroscopy near the 500 nm wavelength. This reaction, known as the Jaffe reaction, also occurs non-specifically with other components in biological fluids. However, the specific color produced with creatine in this reaction is known to degrade rapidly under acidic conditions (Slot et al.). Heinegard and Tiderstrom showed that the difference in color intensity determined before and after the addition of acid is a direct estimate of creatinine concentration in the sample