Application DetailsWestern blot and ELISA. Suggested working dilution for western blot is 1:1,000-1:5,000. The amount of milk per lane can be 0.05 µL-0.1 µL for Western blot. Sample Preparation: Milk should be diluted 1:10 in 0.1M NaOH. The reason for diluting (1:10) in 0.1M NaOH is because the milk protein is easier to dissolve in NaOH. The sample is then further diluted with PBS or other buffer and mixed at 1:1 ratio, to prepare for loading. For example, one can take the 1:10 dilution milk (0.5 µL-1 µL) and add into 9.5 µL or 9 µL PBS and mix with 10 µL SDS-PAGE Sample buffer, boil for 5 minutes, quick spin, and load on the gel. Recommended blocking buffer: TBS with 5% BSA. Recommended antibody dilution buffer: TBST containing 3% BSA. Biosensis recommends that optimal working dilutions should be determined by the end user.
TargetCasein, A1 beta
SpecificityThe antibody is specific to A1 beta casein by western blot. No cross-reactivity with A2 beta casein is seen. Species cross-reactivity not tested.
Target Host SpeciesBovine
Immunogen DescriptionA synthetic peptide (PGPIHNSLP, aa: 78-86) conjugated to KLH has been used as immunogen. Bovine A2 beta casein differs from bovine A1 beta casein by one amino acid (P82 -> H82)
Purity DescriptionAffinity purified chicken IgY.
FormatLiquid in PBS, pH 7.4, containing 0.02% sodium azide as preservative. Refer to the product label for antibody concentration.
Storage InstructionsMaintain unopened vial at -20°C for up to 12 months after date of receipt. After opening maintain at -20°C in undiluted aliquots for up to 6 months. For short-term storage, keep aliquot at 2-8°C for up to one week. Avoid repeated freeze-thaw cycles.
Batch NumberPlease see item label.
Expiration Date12 months after date of receipt (unopened vial).
Scientific BackgroundBovine milk contains two types of beta-casein protein, A2 or A1. Recent studies have shown that milk containing the A1 beta casein protein can contribute to issues including gastrointestinal discomfort after ingestion. There is some evidence of a link between ingestion of A1 beta casein protein and the development of Type 1 diabetes.
Western Blot analysis of cow milk with chicken anti-A1 casein antibody (0.1 µg/mL). Blot was developed with donkey anti-chicken secondary antibody used at 1/4000 dilution. C-1781-100 is specific for A1 protein and does not recognize A2 protein on western blots.
Lane M: Molecular weight marker Lane A1A1: 50 nL milk from the cow bearing A1/A1 alleles Lane A1A2: 50 nL milk from the cow bearing A1/A2 alleles Lane A2A2: 50 nL milk from the cow bearing A2/A2 alleles