Phenylethyl alcohol agar test aka PEA test is performed on a sample of blood to measure the level of Gram Positive Organism in the blood. It is performed to confirm Bacterial Infection and also during the treatment and after the treatment of Bacterial Infection.PEA is a selective medium used to cultivate Gram positive organisms. The active ingredient, Phenylethyl alcohol, inhibits or markedly reduces growth of Gram negative organisms by interfering with DNA synthesis.