| 摘要 |
<p>Errors in the radioisotope dilution assay (RIDA) of the vitamin B12 level of human blood have been traced to the presence of vitamin B12 analogues. These previously unrecognized analogues bind with proteins normally included with binding proteins used in the prior art RIDA techniques. The errors caused by the B12 analogues are avoided by using a composition for binding vitamin B12 which is substantially free of substances which bind vitamin B12 analogues. Moreover, by using both types of binders in separate assays, the amount of analogue present may be arrived at by taking the difference of the assays. Compositions that are effectively substantially pure intrinsic factor (IF) are used as binders.</p> |
