Whole IgG antibodies are isolated as intact molecules from antisera by immunoaffinity chromatography. They have an Fc portion and two antigen binding Fab portions joined together by disulfide bonds and therefore they are divalent. The average molecular weight is reported to be about 160 kDa. The whole IgG form of antibodies is suitable for the majority of immunodetection procedures and is the most cost effective.
Store freeze-dried powder at 2-8°C. When ready to use, rehydrate with indicated volume of d. water and centrifuge if not clear. Product is stable for about 6 weeks at 2-8°C as an undiluted liquid. Prepare working dilution fresh each day. For extended storage after rehydration, add an equal volume of glycerol (ACS grade or better) for a final concentration of 50%, and store at -20°C as a liquid. Note: after the addition of glycerol, the concentration of protein and buffer salts is one-half of the original. Alternatively, aliquot and freeze the product at -70°C or below in the absence of glycerol. Avoid repeated freezing and thawing.
Expiration date: one year from date of rehydration. However, the expiration date may be extended if the product is stored according to the recommendation and the test results are acceptable for its intended use.
1:20,000 - 1:400,000 for ELISA and Western blotting using enzyme-conjugated streptavidin
1:500 - 1:5,000 for enzyme immunohisto/cytochemistry
1:200 - 1:1,000 for flow cytometry and fluorescence immunohisto/cytochemistry
Dilution factors are presented in the form of a range because the optimal dilution is a function of many factors, such as antigen density, permeability, etc. The actual dilution used must be determined empirically.
Biotin-SP is our trade name for biotin with a 6-atom spacer positioned between biotin and the protein to which it is conjugated. When Biotin-SP-conjugated antibodies are used in enzyme immunoassays, there is an increase in sensitivity compared to biotin-conjugated antibodies without the spacer. This is especially notable when Biotin-SP conjugated antibodies are used with alkaline phosphatase-conjugated streptavidin. Apparently, the long spacer extends the biotin moiety away from the antibody surface, making it more accessible to binding sites on streptavidin. Biotinylated antibodies require an additional reagent for visualization. We offer streptavidin and Mouse Anti-Biotin conjugated to fluorophores and enzymes.
This product is for IN VITRO RESEARCH USE ONLY. It is not a medical device and it is not intended for diagnostic or therapeutic purposes.