Mixing small volumes

Add the liquids to be mixed to the test tube. Be sure the mouth of the test tube is pointed away from you and other people. While holding the test tube near its mouth, strike it near the bottom with your index finger until the liquids have been thoroughly mixed.

Alternately, a glass rod may be used to mix liquids in a test tube. Mix by moving the glass rod in an up-and-down, butter churn motion. Be careful not to break through the bottom of the test tube.