Question

A student wants to measure the amount of HRP in their sample using a spectrophotometer. What would you use to create the blank before putting your sample into the spectrophotometer?

A. PBS-BSA
B. Triton-X
C. H2SO4
D. Substrate

Answer 1

To measure the amount of horseradish peroxidase using a spectrophotometer, a blank is needed which usually contains all components except the enzyme. PBS-BSA would be used for this purpose, providing a baseline for the spectrophotometric reading.

Step-by-step explanation:

When using a spectrophotometer to measure the amount of horseradish peroxidase (HRP) in a sample, you would use a blank to calibrate the machine before measuring your actual samples.

The blank should contain all the components of the assay except for the enzyme of interest, HRP, to account for the absorbance of other substances in the mixture. In this context, the most appropriate choice for a blank would be A. PBS-BSA (Phosphate Buffered Saline- Bovine Serum Albumin), as it would provide a baseline by including potential interfering substances (buffers and stabilizers like BSA) but not HRP or its substrate. Choices B (Triton-X) and C (H2SO4) are not typically components of an enzyme assay buffer. Choice D (Substrate) includes the substrate, which should only be present in the actual experiment, not in the blank.