«ALG-CASEIN A1/A2» reagent kit
β‑casein is a protein consisting of a chain of 224 amino acids, which accounts for about 30% of all milk proteins. There are two major variants of β‑casein: A1 and A2. Variant A1 differs from A2 by only one amino acid. As a result, dairy products containing A1 or A2 β‑casein are digested differently. As a result of β‑casein metabolism «opioid peptide» BCM‑7 appears and about 25% of people are sensitive to this component. Some people who believe they have milk intolerance may be sensitive to A1 β‑casein. Consumption of milk with A2 β‑casein reduces acute gastrointestinal symptoms of milk intolerance, while regular milk with A1 β‑casein reduces lactase activity and enhances gastrointestinal symptoms.
The formation of a genetically safe group of highly productive dairy cattle herd is one of the successful approaches in modern animal husbandry to increase the productivity and A2 milk yield without A1 impurities. This approach will not only guarantee the “healthy” A2 milk production, but also completely displace and eliminate the production of A1 milk within 10 years.
There are 3 types of cows
A1/A2 status is determined in cows and bulls by a pair of genes on the 6th chromosome, namely, polymorphic variants of the β‑casein gene β‑CNA1 and β‑CNA2, respectively. Each cow and bull carries two copies of this gene, and two main variants are distinguished – the A1 and A2 β‑casein alleles. Regardless of the breed, a herd of cattle is formed by three types of animals: A2A2 homozygous genotype, A1A1 homozygous genotype and A1A2 heterozygous genotype.
Figures 1 and 2 show the frequency of alleles and genotypes occurrence in various breeds.
To form a prosperous group of high-yielding dairy herd of cattle, it is advisable to select and sort animals and to form a separate herd of only homozygous type A2A2 cows and bulls, which give only A2 milk, gradually increasing the number of such animals and completely excluding the production of A1 milk.
At the current stage, expensive sequencing methods or time-consuming approaches using gel electrophoresis are mainly used for genotyping and certification of cattle. Unlike other cow genotyping technologies based on β‑casein variants, real-time PCR analysis is the fastest, most convenient and affordable method that allows sensitive and specific detection of A1 and/or A2 DNA in samples. This approach is implemented in the ALG-CASEIN A1/A2 reagent kit.
We express our gratitude for the joint development and validation of studies on animal samples to the employees of the Center for Genetics and Reproduction (a branch of Algimed Techno LLC). Services for genotyping of cattle to identify A1 and A2 animals can be ordered on the website – https://labgen.by/
The test principle is based on the amplification of a specific DNA region with allele-specific probes to determine allelic variants of the β‑casein gene (β‑CNA1 and β‑CNA2) in Bos taurus. The accumulation of amplification products is detected by measuring the intensity of the fluorescent signal in real time via the FAM and HEX channels.
The ALG-CASEIN A1/A2 reagent kit includes all the necessary components for real-time PCR: positive, negative and internal control, water, buffers and enzymes.
- Form 1
- Form 2
ALG-CASEIN A1/A2 reagent kit composition (release form 1, 100 reactions):
- A1A2 Casein PCR buffer (2x) – 1,25 ml × 1 pc;
- Water for PCR – 1,25 ml × 1 pc;
- А1А1 PCS – 100 mkl × 1 pc;
- А1А2 PCS – 100 mkl × 1 pc;
- А2А2 PCS – 100 mkl × 1 pc;
- NCS – 250 mkl × 1 pc.
ALG-CASEIN A1/A2 reagent kit composition (release form 2, 1000 reactions):
- A1A2 Casein PCR buffer (2x) – 1,25 ml × 10 pcs;
- Water for PCR – 12,5 ml × 1 pc;
- А1А1 PCS – 500 mkl × 1 pc;
- А1А2 PCS – 500 mkl × 1 pc;
- А2А2 PCS – 500 mkl × 1 pc;
- NCS – 1,5 ml × 1 pc.
- Quick result (90 minutes for analysis);
- Turnkey solution including all necessary reagents;
- Fast, reliable and highly sensitive result;
- Availability of analysis of the obtained results.
- Genomic DNA isolated from Bos taurus tissue samples.
Personnel qualification requirements: only people with the appropriate education and the necessary skills to work in a PCR laboratory are allowed to work with the kit.
The kit is adapted for thermocyclers of plate and rotary type.
Time of the study:
- Time for manual manipulation is 5–15 min;
- Time of the PCR protocol is 71 minutes;
- Total time for analysis is 90 minutes.
- 7.5 genomic copies per reaction.
Shelf life: 12 months.