A test called the HIV 1 & 2, Ab Western Blot is used to find out if someone has the human immunodeficiency virus (HIV). An electric current is used to separate a blood sample for this test. A sheet of blotting paper is then used to transfer it. This is followed by the addition of an enzyme, which results in colour changes that show the existence of HIV antibodies. People who have been exposed to HIV, such as those who engage in unsafe intercourse, share needles, have received blood transfusions, or have any sexually transmitted infections, are required to have this test.