title: Enzyme-Linked Immunosorbent Assays for the Specific and Sensitive Quantification of Methanosarcina mazei and Methanobacterium bryantii.
abstract: Three microtitration plate enzyme-linked immunosorbent assays (ELISAs) have been developed: a competitive ELISA and a two-site (or indirect sandwich) ELISA for Methanosarcina mazei S6 and a two-site ELISA for Methanobacterium bryantii FR-2. The assays were sensitive, with limits of cell protein detection of 3 ng ml, 5 ng ml, and 50 ng ml, respectively, and showed good precision. The M. mazei assays used monoclonal antibodies and were entirely species specific, showing no cross-reaction with methanogens of other genera or with other species of the same genus. The Methanobacterium bryantii assay, which used two polyclonal antisera, showed only a slight cross-reaction with one other Methanobacterium species but no cross-reaction with methanogens of other genera. The use of the ELISAs for quantitative analysis of mixed cultures and of sewage sludge samples was investigated. Sludge diluted at 1:10 or more caused no significant interference in any of the three ELISAs. Various cultures of bacteria, methanogens, and nonmethanogens at a protein concentration of 50 mug ml showed no significant interference in the M. mazei competitive assay and the Methanobacterium bryantii two-site assay, although they did cause falsely low results in the M. mazei two-site assay.
authors.affiliation: AFRC Institute of Food Research, Norwich Laboratory, Colney Lane, Norwich NR4 7UA, United Kingdom.
authors.forename: H A
authors.initials: HA
authors.lastname: Kemp
authors.forename: D B
authors.initials: DB
authors.lastname: Archer
authors.forename: M R
authors.initials: MR
authors.lastname: Morgan