The following guidelines are recommended handling procedures, offered only to assist the user in maximizing product integrity. Scripps Laboratories makes no claims regarding product stability.
- Use either borosilicate glass or polypropylene containers. Do NOT use polystyrene or polyethylene containers.
- For a stock solution, hormones should be reconstituted to ≥1 mg/ml in the presence of a protease-free carrier (0.1-1% ovalbumin, BSA, or gelatin) and a suitable antimicrobial agent. The following general guidelines may be useful:
- Ovalbumin is generally used when assaying for gonadotropin;
- If BSA is used, it must be free of gonadotropins and proteases (either crystalline or RIA grade is generally satisfactory);
- Heat gelatin solutions to 60°C for maximum solubility (1% gelatin for ELISAs, 0.1% for solid phase assays);
- For the pituitary hormones hFSH, hLH, hPRL, and hTSH, the recommended dilution buffer is
10 mM Sodium Phosphate, 150 mM Sodium Chloride, 1 mg/ml BSA, 0.1% Sodium Azide, pH 7.4 is generally satisfactory for hFSH, hLH, hPRL, and hTSH. (Click here to view our Pituitary Hormone Dilution Buffer)
- For hCG and hGH, the recommended dilution buffer is
100 mM Tris, 1 mg/ml BSA, 0.05% Sodium Azide, pH 8.0 is generally satisfactory for hCG and hGH. (Click here to view our hCG & hGH Dilution Buffer)
- Equilibrate the hormone to ambient room temperature before attempting to resuspend. After resuspending with buffer, allow to sit for at least 30 minutes at 2°C to 8°C to ensure complete solubilization.
- Avoid re-lyophilization, as this will cause the hormone to lose significant activity. If material is re-lyophilized, it should be assayed again prior to use.
- Do NOT freeze-thaw reconstituted samples repeatedly. The reconstituted hormone should be subdivided into working aliquots and stored at or below -15°C as soon as possible after resuspension.
- Reconstituted samples are normally stable for at least 2-6 months when stored frozen; however, this depends on the hormone concentration, buffer/stock solution composition, and handling conditions.