Radioassay of vitamin B-12 employing bentonite

Patent · Tue Feb 10 04:00:00 EST 1976

OSTI ID:7193092

Lewin, N; Fries, J E; Richards, C S

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. 7 claims, 1 drawing figure.

• Assignee: Bio-Rad Labs.
• Patent Number(s): US 3937799
• OSTI ID: 7193092
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
BENTONITE
BLOOD SERUM
IMMUNE SERUMS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MINERALS
RADIOASSAY
RADIOIMMUNOASSAY
TRACER TECHNIQUES
VITAMIN B GROUP
VITAMIN B-12
VITAMINS