What is a special test strip that reacts to certain substances in urine or blood called?

The term for a special test strip that reacts to certain substances in urine or blood is known as a reagent strip. These strips are coated with specific chemicals that will yield a color change in response to the presence of particular substances, such as glucose, protein, or pH levels in the sample. This color change allows for a quick and effective assessment of various components in bodily fluids, aiding in the diagnosis and monitoring of health conditions.

Reagent strips are widely used in clinical laboratories and home testing kits because they provide immediate results and are relatively easy to interpret. Other names might exist in different contexts, but "reagent strip" is the most commonly used and recognized terminology in medical and laboratory settings.

In contrast, the other terms have specific definitions or uses that do not apply directly to the context of testing bodily fluids. For instance, testing strips could be a broader category that includes various types of strips, while indicator strips are often used in chemistry to indicate the presence of acidity or alkalinity but may not always be specific to biological substances. Litmus strips are specifically designed to test pH levels and do not provide information about multiple substances present in a sample. Thus, the specificity and intended use of reagent strips in healthcare make it the correct answer