What is test tube brush function?

A test tube brush is used to clean the inside of test tubes and other small or narrow lab equipment. The brush is made up of stiff bristles that are attached to a long handle, making it easy to reach all areas of the test tube. The bristles are usually made of nylon, polyester, or natural animal hair. They are effective at removing stubborn dirt, stains, and residue that cannot be removed by simply rinsing with water. The use of a test tube brush is important in many scientific experiments as it ensures that the samples are not contaminated by any previous residues present in the test tube.