The effect of pH, separately for with or without added saponin, on assayable RCF compared with 10 g/L AA, pH 2.7 (lysate, pH 4.0), was assessed by parametric one-way ANOVA and the least significant difference test.
The effect of pH on assayable RCF was assessed by parametric one-way ANOVA and the least significant difference test.
With water as the diluent, the effect on assayable RCF (a) without saponin, (b) without saponin + freezing-thawing, and (c) with saponin was assessed by parametric one-way ANOVA and the least significant difference test.
The addition of saponin to the 10 g/L AA diluent, pH 2.7, 4.0, and 4.25 (whole blood lysates, pH 4.0, 4.7, and 5.2, respectively), did not produce significantly different assayable RCF concentrations.
Subsequent to erythrocyte hemolytitis in 1% AA, RCF is deconjugated with naturally occurring plasma folate conjugase enzyme, with reaction time being the only variable utilized, at any given temperature, to optimize assayable folate.
At this point, it may be pertinent to note that although AA technically has the ability to act as a prooxidant (especially in the presence of metal ions), the addition of AA to hemolysates has always resulted in an increase of assayable folate, thus ruling out the probability of it acting as a prooxidant in the context of erythrocyte folate analysis.
After 1 day of storage, AA (pH 2.8) hemolysates had an assayable folate concentration 65% higher than AA-pH 6.0 hemolysates (22).