Stool samples can help doctors diagnose some health conditions. Tips for collecting a stool sample include urinating before collecting the sample and using any tools that the sample kit provides.

A clean catch urine sample or specimen is one of the least invasive procedures for a urine culture or urinalysis. The clean catch method aims to prevent bacteria from the skin of the penis or vagina ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Representative sampling and random sampling ...