Long Term Storage of Antibody Sensitized Millititer (Trademark) Immunoassay Plates for the Identification and Quantitation of Francisella Tularensis.

摘要

In this report we have described a modified procedure for the 'sandwich' fluorogenic enzyme-linked immunosorbent assay (FELISA) for the detection and quantitation of antigen, in which immunoassay plates were pre-coated with capture antibody or, alternatively, with capture antibody and blocking reagent, and stored frozen for periods up to 1 yr. Using Francisella tularensis as a model, two different identification protocols were employed. In the first, antibody-sensitized immunoassay plates stored frozen at -70 C were challenged with whole cells or with outer membrane protein of F. tularensis. In these experiments, there was no loss of sensitivity for the detection and quantitation of the antigen, when compared with freshly prepared immunoassay plates. This procedure took 5 h compared to more than 6 h required for performance of the assay using freshly prepared plates. In the second protocol, antibody-coated immunoassay plates were blocked with bovine serum albumin and stored frozen at -70 C for periods of up to 1 yr. This latter procedure shortened the assay time to 3 h while maintaining the same degree of sensitivity (10 fg (10-14 g) mL-1 of outer membrane protein and 100 colony forming units mL-1 of F. tularensis whole cells) as that achieved with freshly coated plates. Keywords: Nitrocellulose membranes, Enzyme-linked immunosorbent assay, Fluorogenic, Francisella tularensis, Outer membrane protein. (kt)