Nomenclature: Hydrocortisone-3-CMO-BSA; 4-Pregnen-11b,17,21-triol-3,20-dione 3-Carboxymethyloxime-BSA
11b, 17a, 21-Trihydroy-4-Pregnene-3, 20-dione 3-(0-carboxymethyl)oxime
Solubility of BSA Conjugates:
Haptens with ~30 steroids per molecule are designed for raising antibodies. They are virtually insoluble in water and buffer without detergents. The lack of solubility in water arises from both the steroid content and crosslinking. We suggest solubilization with a detergent with vigorous stirring, for example Freund's adjuvant (which contains a detergent) works well. Place the steroid onto the solution, not the other way round.
Dissolving BSA conjugates in water for cell culture experiments with molar ratios of greater than 10 moles of steroid per mole of BSA is almost impossible.
Storage and Stabilty:
Lyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile buffer. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.