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Journal of Clinical Pathology logoLink to Journal of Clinical Pathology
. 1964 Nov;17(6):660–665. doi: 10.1136/jcp.17.6.660

Microbiological assay of folic acid activity in human serum

G H Spray 1
PMCID: PMC480852  PMID: 14227437

Abstract

A method is described for the microbiological assay of folic acid activity in serum with Lactobacillus casei as test organism and a modified medium in which the organism gives a greater growth response than in media previously detailed. The results of experiments carried out to validate the use of this medium are shown.

In 94 control subjects levels of folic acid activity in the serum ranged from 2· to 28 mμg./ml. (mean 7·8). The values in nine out of 10 patients with megaloblastic anaemia due to deficiency of folic acid were 1·0 mμg./ml. or less and one result was 2·0 mμg./ml. In six patients with megaloblastic anaemia associated with pregnancy the results ranged from 0·7 to 4·0 mμg./ml., and in untreated pernicious anaemia 28 out of 31 results were within or above the control range and three values were just below the lower limit of normal.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. CHANARIN I., BERRY V. ESTIMATION OF SERUM L. CASEI ACTIVITY. J Clin Pathol. 1964 Mar;17:111–113. doi: 10.1136/jcp.17.2.111. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. COOPER B. A., LOWENSTEIN L. Evaluation of assessment of folic-acid deficiency by serum folic-acid activity measured with L. casei. Can Med Assoc J. 1961 Oct 28;85:987–988. [PMC free article] [PubMed] [Google Scholar]
  3. DAVIS R. E., KELLY A. The microbiological assay of serum folic acid activity. Aust J Exp Biol Med Sci. 1962 Dec;40:437–444. doi: 10.1038/icb.1962.48. [DOI] [PubMed] [Google Scholar]
  4. GROSSOWICZ N., MANDELBAUM-SHAVIT F., DAVIDOFF R., ARONOVITCH J. Microbiologic determination of folic acid derivatives in blood. Blood. 1962 Nov;20:609–616. [PubMed] [Google Scholar]
  5. HERBERT V., BAKER H., FRANK O., PASHER I., SOBOTKA H., WASSERMAN L. R. The measurement of folic acid activity in serum: a diagnostic aid in the differentiation of the megaloblastic anemias. Blood. 1960 Feb;15:228–235. [PubMed] [Google Scholar]
  6. HERBERT V. The assay and nature of folic acid activity in human serum. J Clin Invest. 1961 Jan;40:81–91. doi: 10.1172/JCI104240. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. SPRAY G. H. An improved method for the rapid estimation of vitamin B12 in serum. Clin Sci. 1955 Nov;14(4):661–667. [PubMed] [Google Scholar]
  8. WATERS A. H., MOLLIN D. L. Studies on the folic acid activity of human serum. J Clin Pathol. 1961 Jul;14:335–344. doi: 10.1136/jcp.14.4.335. [DOI] [PMC free article] [PubMed] [Google Scholar]

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