A1 and A2 milk are two types of milk that differ in their protein composition. A1 milk contains the A1 beta-casein protein, while A2 milk contains the A2 beta-casein protein. A1 milk is the most common type of milk in the world. It is produced by cows that have both A1 and A2 beta-casein proteins in their milk. A2 milk is produced by cows that only have A2 beta-casein proteins in their milk. This type of milk is becoming more popular, but it is still not widely available.
The test method we follow
PCR, or polymerase chain reaction, is a molecular biology technique that is used to amplify and quantify DNA. QPCR amplify the beta-casein gene and then quantify the amount of A1 and A2 beta-casein. The primers that are used to amplify the DNA are specific for the A1 and A2 alleles. This means that the primers will only amplify the DNA from the cow if the cow has the A1 or A2 allele. If the DNA is amplified from the A1 allele, the cow is A1/A1 or A1/A2. If the DNA is amplified from the A2 allele only, the cow is A2/A2.
The QPCR test for A1 and A2 milk is a sensitive and specific test. It can detect even small amounts of A1 beta-casein in A2 milk.