Radioassay of vitamin B-12 employing bentonite
US3937799A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1974 |
| Grant date | Feb 10, 1976 |
| Priority date | — |
| Expiry date | Aug 26, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/82
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Radioassay for vitamin B-12 using the unknown quantity of non-radioactive vitamin B-12 released from serum mixed with the radioactivity of a known quantity of radioactive vitamin B-12 tracer. A solution of intrinsic factor having a binding capacity less than the quantity of serum vitamin B-12 and radioactive vitamin B-12 is used to bind a portion of the vitamin B-12 mixture. The vitamin B-12 not bound to intrinsic factor is removed by addition of a bentonite-containing tablet. The quantity of radioactive vitamin B-12 bound to intrinsic factor is compared with standard values and the unknown serum vitamin B-12 obtained. In the steps of the procedure the acid assay medium is pre-combined with the radioactive tracer so that the radioactive vitamin B-12 tracer receives the same treatment as serum vitamin B-12. Certain of the other reagent solutions are pre-combined and the concentration of the components adjusted so that the volume used of each of these other reagent solutions is the same in different assay steps. Thus, fewer pipetting steps are necessary.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.