Lactobacillus casei microbiological assay of folic acid derivatives in 96-well microtiter plates.

TLDR

Microbiological assay remains widely used for estimating folic acid derivatives in serum and other biological samples. The authors propose a modification of this assay by employing 96‑well microtiter plates. The modified assay uses 96‑well microtiter plates with computer‑interfaced readers and data‑reduction software. The 96‑well procedure shortens assay time, reduces reagent costs, produces equal growth responses for all folic acid derivatives tested, and agrees well with the standard bioassay for rat liver extracts.

Abstract

Microbiological assay is still widely used for estimating folic acid derivatives in serum and other biological samples. We describe here a modification of this procedure involving use of 96-well microtiter plates. This procedure, used with modern, computer-interfaced microtiter-plate readers and data-reduction software, greatly shortens the time and minimizes reagent costs for this assay. Under the conditions of our assay procedures, all folic acid derivatives tested gave equal growth response for Lactobacillus casei. Results for assays of rat liver extracts showed excellent agreement between the standard bioassay and the 96-well procedure.