for vitamin [B.sub.12] performed in 96-well microtitre plates.
Demonstration of vitamin B12 analogues in human sera not detected by microbiological assay
. Br J Haematol 1982; 51:171-3.
Different laboratories and cobalamin assay methods often differ in the reference intervals they produce, but classification discrepancies have been relatively few, at least among isotopic and microbiological assays
Currently, the major analytical approaches used for folate determination are microbiological assays
, radioassays, chemiluminescence assays, HPLC, and ion-capture assays.
We studied the distribution of folates in DSS, using a microbiological assay
, and considered that a 6.35-mm punch represented 10 [micro]L of serum for the purposes of calculation.
A recent study of red cell folate extraction (1), using a microbiological assay
, challenged these assumptions.
Deconjugated samples were remixed gently by multiple inversions and diluted 20-fold by reverse-pipetting 100 [micro]L into a 2-mL screw-cap microcentrifuge tube containing 1.9 mL of 0.1 mol/L sodium phosphate buffer, pH 6.2 (so that samples could be added to the microbiological assay
at the same pH as the assay medium).
It has been our consistent finding with the microbiological assay
, however, that the converse is true; we find lower erythrocyte folates in those homozygous for the variant compared with those who are heterozygous or wild-type .
The responses of Escherichia coli and Bacillus cereus were examined under controlled laboratory conditions for 48 hours using spectrophotometry, viable counts and standard microbiological assays
. Overall, the results showed E.
* ATCC Minis, which are ready-to-use glycerol stocks of industry-recommended ATCC quality control strains used in performance assessments of microbiological assays
and instruments; and