RESUMO
The protein precipitates discarded during the extraction process of the Lactobacillus leichmannii vitamin B12 assay have been shown to contain significant amounts of vitamin B12. This loss of vitamin B12 provide a satisfactory explanation for many of the descrepancies between the serum vitamin B12 values obtained by the L. leichmannii method and the radio-isotopic method of Raven et al (1969). It is possible to produce lower results by the method of Raven et al (1969)by incorporating into that method the L. leichmannii extraction process; it is also possible to produce higher results by the L. leichmannii method using a papain extraction process.
Assuntos
Vitamina B 12/isolamento & purificação , Lactobacillus , Papaína , Ensaio Radioligante/métodos , Estatística como Assunto , Vitamina B 12/sangue , Deficiência de Vitamina B 12RESUMO
The first commercial kit for the radioisotopic assay of vitamin B(12) in serum-the Phadebas B(12) Test produced higher values than the radioisotopic method of Raven, Robson, Walker, and Barkham (1969) and the Lactobacillus leichmannii microbiological assay. Its normal range was 300-1100 pg/ml and its reproducibility was similar to that of the other radioisotopic method. It should be possible to lower the results obtained by the Phadebas method by modifying its standard curve and to reduce the time taken for the assay by shortening its incubation period.
Assuntos
Vitamina B 12/sangue , Anemia Perniciosa/sangue , Anemia Perniciosa/diagnóstico , Bioensaio , Radioisótopos de Cobalto , Humanos , Lactobacillus , Métodos , Fatores de TempoAssuntos
Isótopos do Cobalto , Euglena gracilis , Lactobacillus , Vitamina B 12/sangue , Anemia Macrocítica/sangue , Anemia Macrocítica/tratamento farmacológico , Anemia Perniciosa/sangue , Bioensaio , Contagem de Eritrócitos , Ácido Fólico/uso terapêutico , Deficiência de Ácido Fólico/sangue , Deficiência de Ácido Fólico/tratamento farmacológico , Gastrectomia , Hemoglobinas/análise , Humanos , Métodos , Reticulócitos , Deficiência de Vitamina B 12/sangueRESUMO
An improved and simplified method is described for the measurement of vitamin B(12) in serum using intrinsic factor, (57)CoB(12), and coated charcoal. The extraction of serum in the presence of cyanide and the incorporation of B(12)-deficient serum into the intrinsic factor control has increased the accuracy of the method for both sera and crystalline B(12) solutions. There are interesting differences between the results obtained for some sera by the isotope and L. leichmannii methods and the reasons for these differences are discussed.
