| abstract |
A serum sample is heated at an alkaline pH to release folate and vitamin B12 from endogenous binders. A simultaneous radioassay for folate and vitamin B12 is effected by contacting the sample with binder for folate, binder for vitamin B12, folate labeled with one radioactive isotope and vitamin B12 labeled with another radioactive isotope, followed by separation of bound and free portions, and determination of the radioactivity of at least one of the portions. The amounts of folate and vitamin B12 present in the sample may be determined from standard curves. |