Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 29

The principle of the protein error of indicators reaction is that:

A. Protein keeps the pH of the urine constant

B. Albumin accepts hydrogen ions from the indicator

C. The indicator accepts hydrogen ions from albumin

D. Albumin changes the pH of the urine

Step 1 of 2

Protein error of indicators:

It is a tradition method of testing protein in reagent strips.

• Protein error of indicators principle is colorimetric reaction.

• Normally in response to specific pH range, indicators produces particular color, in contrary to this, in the constant pH also, indicators change color when protein exist.

o This is due to albumin (protein) which accepts hydrogen ion from indicator.

• More amino groups are available in albumin for accepting the hydrogen ions compared to other protein.

Therefore, principle reaction in protein error of indicators, “from the indicator, albumin accepts hydrogen ions” .Hence, the correct answer is option.