Casein is the largest group of proteins in milk, making up about 80% of total protein content. There are several types of casein in milk. ?-casein is the second most prevalent and the two most common forms of it are, A1 ?-casein and A2 ?-casein. Regular milk contains both A1 and A2 ?-casein, but A2 milk contains only A2 ?-casein. A1 is considered a genetic mutation that causes development of unwanted health conditions and illnesses among consumers. Growing number of studies have enumerated the benefits of A2 milk, and the health risks associated with continuous consumption of A1 milk. PCR is a method of A1 and / or A2 Genotyping that allowspecific detection of A1 and / or A2 DNA from milk samples. Hi-PCR® A1A2 Probe PCR Kit is designed to detect the A2 and A1 alleles separately, along with internal control, in a single tube reaction.