The pH pad on the reagent strip contains methyl red and bromothymol blue indicator dyes. The color change that occurs in this test area correlates with the urine's pH. Sensitivity to pH ranges from 5.0 (acid pH with a red-orange color on the reagent strip) to 9.0 (alkaline pH with a blue-green color on the reagent strip). Physiological urine pH ranges from 5.0 to 8.0.
Note: The first morning urine sample of a healthy individual usually yields a urine pH of 5.0 to 6.0.
