Purification of intrinsic factor, and removal of R-protein using cobinamide
US5459242A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1993 |
| Grant date | Oct 17, 1995 |
| Priority date | — |
| Expiry date | Mar 16, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/54353
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for purifying an aqueous intrinsic factor solution which contains R-protein is disclosed. The method involves adding to the intrinsic factor solution an amount of colloidal silica to disperse lipid emulsion, an amount of cobinamide sufficient to bind substantially all of the R-protein in the solution and an amount of an intrinsic factor affinity resin sufficient to bind the intrinsic factor in the solution, washing the bound cobinamide and the R-protein from the resin, eluting the intrinsic factor from the resin, and dialyzing the eluted intrinsic factor. The purified intrinsic factor possesses less than 0.004 percent cross reactivity with cobinamides, and at least 95 percent of the proteins in the purified material can bind cobalamins. A conjugate of microparticles and the purified intrinsic factor is also disclosed, as is a kit for conducting an assay for cobalamins which includes a conjugate of microparticles and purified intrinsic factor. A method for conducting an assay for cobalamins, which method involves the use of a conjugate of microparticles and purified intrinsic factor is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.