title: Nonisotopic binding assay for measuring vitamin B12 and folate in serum.
abstract: We evaluated a nonisotopic method (CEDIA; cloned enzyme donor immunoassay) for estimating vitamin B12 and folate in serum. The assays were performed with a Cobas-Mira analyzer. Intra-assay CVs were from 3.7% to 11.0% for vitamin B12 and from 1.2% to 10.7% for folate. Interassay CVs ranged from 9.5% to 11.9% for vitamin B12 and from 6.1% to 18.5% for folate. Linearity was satisfactory, with analytical recovery of 94% at 8.7 and 25.4 nmol/L for folate and 280 and 554 pmol/L for vitamin B12. The detection limit was 3.6 nmol/L for folate and 12.3 pmol/L for vitamin B12. Results of this assay correlated well with those of a conventional radioassay: r = 0.98 for vitamin B12 (n = 51) and r = 0.97 for folate (n = 57). The CEDIA was easy to perform but appeared to be unreliable for use with samples from myeloma patients.
authors.affiliation: Department of Clinical Chemistry and Hematology, Hospital De Lichtenberg, Amersfoort, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van der Weide
authors.forename: H C
authors.initials: HC
authors.lastname: Homan
authors.forename: E
authors.initials: E
authors.lastname: Cozijnsen-van Rheenen
authors.forename: Y
authors.initials: Y
authors.lastname: Vivié-Kipp
authors.forename: J
authors.initials: J
authors.lastname: Poortman
authors.forename: R J
authors.initials: RJ
authors.lastname: Kraaijenhagen
mesh_terms: D005492:Folic Acid / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D010266:Paraproteins; D011786:Quality Control; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D010266:Paraproteins; D005492:Folic Acid; D014805:Vitamin B 12