Effect of storage on the apparent concentration of folate in erythrocytes, as measured by competitive protein binding radioassay.
The folate concentration in erythrocytes changes during incubation. Using whole blood samples and washed erythrocytes, I find greatly increasing concentrations of folate in washed samples at 37 degrees C, decreasing concentrations in whole-blood samples. This difference in behavior depends on a thermostable, ultrafiltrable factor in plasma. Exclusion of glucose or addition of fluoride did not affect these results. Decreasing concentrations of folate were found when iodoacetate or acetylphenylhydrazine was present. At 4 degrees C the concentrations of folate were stable for 72 h. I discuss possible explanations for the observed changes and their practical significance.
D001667:Binding, Competitive; D001793:Blood Preservation; D004912:Erythrocytes / Q000032:analysis*; D005492:Folic Acid / Q000097:blood*; D006801:Humans; D008722:Methods; D011485:Protein Binding; D013997:Time Factors
D005492:Folic Acid