How is DNA fingerprinting performed?

Blood sample from a vein: DNA that is used to establish paternity is collected from a blood sample. The health professional drawing blood will:

• Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
• Clean the needle site with alcohol.
• Put the needle into the vein. More than one needle stick may be needed.
• Attach a tube to the needle to fill it with blood.
• Remove the band from your arm when enough blood is collected.
• Apply a gauze pad or cotton ball over the needle site as the needle is removed.
• Apply pressure to the site and then a bandage.

Blood sample from a heel stick: If a DNA blood test is done on a baby, a heel stick will be done instead of a blood draw from a vein.

For a heel stick blood sample, several drops of blood are collected from the heel of the baby. The skin of the heel is cleaned with alcohol and then pricked with a small, sterile lancet. Several drops of blood are collected inside circles on a specially prepared piece of paper. When enough blood has been collected, a gauze pad or cotton ball is placed over the puncture site. Pressure is applied to the puncture site briefly and then a small bandage is usually placed over it.

DNA can be collected from dried blood, skin, saliva, hair, urine and semen. Bone and teeth samples are used when a body is badly decomposed.