Measurement of serum folate by 75Se-selenofolate radioassay. Results of a multi-institutional clinical trial.

The authors report the multi-institutional evaluation of a radioassay for serum folate utilizing a gamma-labeled folate analog (75Se-pteroyl-L-methylselenocysteine). The assay is run as a one-step simultaneous addition at ambient temperature and is completed within 45 minutes. The assay data were reproducible within four study centers and correlated with both the Lactobacillus casei diagnostic groups and the clinical pictures.