Abcam’s Phosphate Buffered Saline (PBS) Casein ELISA Reagent consists of many phosphoserine groups that function to bind Ca²⁺. The solution is ready for dilution to specific application requirements. ab171532 contributes to the minimization of non-specific interactions of the secondary reagents with each other and with the primary solid phase binding sites. The high blocking efficiency of casein is due to its content of small molecular weight proteins. Phosphate Buffered Saline (PBS), pH 7.4, is a poor buffer above pH 7.5. Phosphate buffer should not be used in assays where competition for phosphate groups or complex formation with a metal ion is essential for the enzyme activation. Phosphate ions will inhibit carboxypeptidiase, carboxylase, urease, muscle diaminase, formase and phosphoglucomutase.

Storage Instructions:
This product should be clear and colorless in appearance. To minimize the risk of contamination, a fresh working solution should be prepared each day or store unused working solutions at the recommended storage temperature. If proper technique is not performed the possibility of introducing contaminants is always possible.

Product Use:
ab171532 should be diluted with reagent quality water. To produce a 1X working solution, dilute 1 mL of Phosphate Buffered Saline (PBS) Casein ELISA Reagent in 4 mL reagent quality water. To use as a blocking reagent, treat target surface by covering completely with 1X solution. To use as a diluent, dilute antigen/antibody to desired concentration in 1X solution and treat surface by covering completely. When using 1X solution for coating plates, best results are obtained following an overnight incubation at +4°C.