Chromogens and Quality Control in Reagent Strip Testing

Potassium Iodide changes color from yellow to brown when reacting with the urine specimen.

Tetramethylbenzidine changes color from yellow to green when reacting with the urine specimen.

It is recommended to leave the reagent strip in the urine for an extended period to ensure accurate testing.

Interchanging reagent strips and color charts from different manufacturers is acceptable in quality control procedures.

Refrigerated specimens should be used immediately without waiting for them to return to room temperature when using reagent strips.

The reagent strip technique involves dipping the strip into a poorly mixed urine sample at room temperature.

Each reagent pad on the strip contains the same reagents for one reaction.

The colors generated on the reagent strip are compared against a universal color chart.

The principle behind urine glucose testing using reagent strips involves a single enzymatic reaction.

H2O2 produced in the first process of urine glucose testing will inhibit the indicator from changing color.

Absence of an absorbent pad can be compensated by using tissue during the reagent strip technique.

Reagent strips have completely replaced manual methods involving various chemicals in urine analysis.

It is recommended to refrigerate urine samples for chemical examination to preserve their quality.

Touching the chemical pads of reagent strips with fingers does not affect the accuracy of the test results.

Running positive and negative controls is necessary only when questionable results are obtained in urine analysis.

Manual methods using tablets or liquid chemicals are preferred over reagent strips for highly pigmented urine samples.