14/12/2024
The creatinine enzymatic method and the Jaffe reaction are both used to measure serum creatinine levels, but they differ in their chemical principles and accuracy.
1. Jaffe Reaction:
Principle: The Jaffe method is a colorimetric assay where creatinine reacts with alkaline picrate to form a red-orange complex.
Advantages:
Simple and cost-effective.
Historically used as a standard method for creatinine measurement.
Disadvantages:
Prone to interference from substances like proteins, glucose, and ketones, which can cause false positives.
Less specific than the enzymatic method, as it can overestimate creatinine levels.
2. Enzymatic Method:
Principle: The enzymatic method involves using specific enzymes, typically creatininase and creatinase, to break down creatinine in a reaction that produces a measurable change in absorbance (usually a decrease in the substrate or a color change).
Advantages:
More specific and accurate than the Jaffe method.
Less interference from non-creatinine substances.
Disadvantages:
More complex and expensive than the Jaffe reaction.
Requires more advanced instrumentation.
Summary of Key Differences:
Specificity: The enzymatic method is more specific and accurate, whereas the Jaffe method is less specific and can be affected by interfering substances.
Cost: The Jaffe method is generally cheaper and simpler.
Interference: The Jaffe reaction is more prone to interference from other substances in the sample, leading to possible inaccuracies.
Sensitivity: Enzymatic methods tend to be more sensitive and provide a more reliable measurement of creatinine.
In clinical settings, the enzymatic method is increasingly preferred due to its accuracy and reduced susceptibility to interference.
