OPI Supplement (100×)
OPI supplement is a solution of oxaloacetate, pyruvate, and insulin that helps support the growth of hybridoma and myeloma cells at low densities. It is not required for high-density culture. To prepare 100 mL of 100× OPI, dissolve 1.5 g of oxaloacetate and 500 mg of sodium pyruvate in 100 mL of H2O suitable for tissue culture work. Add 2000 IU of bovine insulin. Filter-sterilize and dispense in sterile tubes in 2.0-mL aliquots. Freeze at −20°C. OPI is stable for 6 mo to 1 yr when stored at −20°C.
