Estimation of serum L. casei activity

Abstract

Measurement of the serum Lactobacillus casei (`folic-acid') activity is widely used as an index of folic-acid deficiency. Present methods of assay result in recovery of about half the active material in normal serum. A modified method of assay is described which gives higher L. casei values and a clearer distinction between the sera of normal subjects and of patients with folic-acid deficiency.