Sensitive avidin-biotin amplified fluorogenic enzyme immunoassay using biotinylated monoclonal antibodies for the identification and quantitation of virus

Rapid immunofiltration assay of Newcastle disease virus using a silicon sensor

A rapid nonradioactive sandwich immunoassay which utilizes biotin-streptavidin mediated filtration capture of immune complexes in conjunction with a silicon sensor was developed for the detection of virus. Using purified Newcastle disease virus as a model, the lower limits of detection (LOD) were determined for a number of immunoassay configurations employing both monoclonal and polyclonal antibodies. The LODs ranged from 1.3 ng/ml (sample volume of 100 microliter) for an incubation of 60 min to 400 ng/ml for a 1 min incubation. The sandwich immune complexes were formed from one-step incubation of antibody and antigen. No 'hook' effects were observed over a wide range of analyte concentrations. The assays were easy to perform and required a total time equal to the incubation period plus about 5 min. The assay format is suitable for virus, bacteria and protein antigens. New assays can be developed and optimized readily, often within 1 day.

A sensitive fluorogenic enzyme linked immunosorbent assay for the detection of Vipera russelli venom

A highly sensitive fluorogenic enzyme-linked immunosorbent assay (FELISA) has been adapted for the detection of Vipera russelli venom. The assay sensitivity was observed to be 0.1 pg/ml (1 x 10(-13) g/ml). Venoms from snakes of the Vipera group exhibited a high degree of cross-reactivity when tested with the antibody raised against V. russelli venom. With the exception of venom from Naja naja, all the tested venoms from unrelated families also showed cross-reactivity. This procedure is useful for detecting snake venom or its components in biological samples.