Casein Microwell

Allergies to cow’s milk are the most common food allergy, affecting roughly 2.5% and 0.3% of adults in the US. Casein is the major protein in milk (80% of total milk proteins) and constitutes a major allergen of clinical importance. Because it is present at high levels in milk, casein is a useful indicator of the presence of milk residue. Casein is used widely in the food industry, along with other derivatives and isolates from milk, and can be found in such unexpected items such as processed meats, non-dairy creamers, canned fish and wines.  Companies producing non-dairy products should ensure their raw and finished products have not been contaminated with milk protein during manufacture, to prevent possible allergic responses in sensitized individuals.

Intended Use

The ELISA SYSTEMS® Casein Residue Detection Kit is an enzyme-linked immunosorbent assay (ELISA) that may be used to screen food products for the presence of heat stable milk residues introduced into foods via cross-contamination during manufacturing or direct contamination of raw ingredients. This assay is a rapid and reliable test that significantly reduces the time required to screen food products for the presence of milk.

Assay Principles

The ELISA SYSTEMS® Casein Residue Detection Kit is based on the sandwich enzyme-linked immunosorbent assay format. The food sample is first subjected to an extraction procedure and then tested by ELISA for the presence of casein. The results may be quantified by comparing the test results against results obtained from protein standards supplied in the kit. Results are expressed in terms of ppm skim milk powder equivalents.


(Product code: EC52310)

Performance Characteristics

Range of Quantification: 0.1 – 1.0 ppm Skim Milk Powder equivalents
Sample Preparation Time: ~15 min
Test period: ~45 min