This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Which of the following estimates blood creatinine level most accurately 
Select and explain. 
A. Jaffe method, B. Kinetic jaffe method, C. Technicon method, D. Enzyme assay
D: Enzyme assay
Answer: D: Enzyme assay 
Explanation: D i.e. Enzyme assay Gas chromatography - isotope dilution mass spectrometry (GC- IDMS) is considered the method of choice for establishing the true concentration of creatinine in serum because of its excellent specificity > HPLC > Enzyme assay > Alkaline picrate methodsQ.