Vitamin B.sub.12 and labelled derivatives for such assay
US4465775A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 1982 |
| Grant date | Aug 14, 1984 |
| Priority date | — |
| Expiry date | May 24, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/82
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Vitamin B.sub.12 in liquid samples, such as human serum or human plasma, is assayed by a competitive binding technique using intrinsic factor and certain labelled vitamin B.sub.12 derivatives. The labelled derivatives are formed from the (d)-monocarboxylic acid isomer of vitamin B.sub.12, which isomer is free from other monocarboxylic acid isomers (and derivatives thereof) of vitamin B.sub.12, by binding to the (d)-isomer, via the carboxylic group, a compound which is itself a label (e.g. an enzyme) or which comprises a label (e.g. a fluorophore), or to which a label is attached (e.g. a histidine ester to which .sup.125 I is attached). The labelled derivatives of the (d)-monocarboxylic acid of vitamin B.sub.12, free from other isomeric monocarboxylic acids and derivatives, are novel and constitute one aspect of the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.