Mouth swabs are a means of sampling used to gather samples of body fluids. A mouth swab or buccal swabs is essentially a piece of sterile cotton or gauze which is rubbed against a given part of the body to collect blood, saliva etc. In a DNA test, the swab is simply rubbed on the inside of the mouth (hence, referred to an oral or buccal swab) in order to collect the cells that contain the DNA needed for the test. Doing such swabs causes no discomfort whatsoever to who is taking the swab. The company you have purchased your home DNA Test Kit normally supplies that required swabs. Our Sample Collection guide provides more information regarding swabs.