Patent ID: 7790363

Claim:
A method for determining the quantity of vitamin B 12 in a biological sample, said method comprising the steps of: (a) combining said biological sample with paramagnetic microparticles coated with a purified recombinant porcine intrinsic factor, wherein the amino acid sequence of said porcine intrinsic factor is identical to an amino acid sequence comprising SEQ ID NO: 3; (b) allowing vitamin B 12 present in said sample to bind to said paramagnetic microparticles coated with said porcine intrinsic factor; (c) adding conjugate capable of undergoing chemiluminescent reaction to said mixture of step (b); (d) causing said chemiluminescent reaction to occur; and (e) measuring the resulting chemiluminescent reaction as relative light units to determine the quantity of vitamin B 12 in said biological sample.