Which of the following lists the two methods of lactate determination described?

• A. Wacker/UV method and Colorimetric method (Lactate oxidase, PEROXIDASE)
• B. Wacker/UV method and Enzymatic method
• C. Colorimetric method and Fluorometric method
• D. HPLC method and Colorimetric method

Answer: (A)

Lactate determination can be done by a chemical oxidation method and by an enzymatic colorimetric method. The Wacker/UV approach uses a chemical oxidation where lactate is converted to pyruvate under palladium(II) chloride (with copper co-catalyst) and the reaction is measured by UV absorbance. This gives a direct, spectrophotometric readout without enzymes.

The colorimetric method relies on an enzyme cascade: lactate oxidase converts lactate to pyruvate and hydrogen peroxide. The hydrogen peroxide then reacts with a peroxidase and a chromogenic substrate to produce a colored product that is read photometrically. This approach is widely used because it translates lactate levels into a measurable color change.

Other methods like HPLC or fluorometric techniques exist for lactate, but they are not the two methods described in this context. Therefore, the combination of the Wacker/UV chemical oxidation and the enzymatic colorimetric lactate oxidase–peroxidase method best matches the described pair.