Application of Immunoblotting for Dietary Analysis

Abstract

Information on trophic interactions within a community is important for answering questions concerning energy flow and the effects of predation on community structure. Conventional visual analysis of stomach contents is often complicated by the differential digestion of prey, mastication of prey, ingestion of only fluids from prey, and small sizes of both predators and prey. Serological methods have been utilized to alleviate some of these difficulties. In most cases polyspecific antisera produced against whole-organism extracts of suspected prey items have been utilized to detect prey antigens with immunoprecipitation techniques. Passive immunodiffusion tests have been utilized extensively because of their speed and relative simplicity (e.g., Young, 1980; Adams, 1981; Giles and Phillips, 1985; Feller, 1986). Increased sensitivity and specificity of serological analysis have been achieved by utilizing immunoelectrophoretic techniques (Healy and Cross, 1975; Grisley and Boyle, 1985). These immunoassays have proven adequate in situations for which the diversity of potential prey is low (so most serological cross-reactions can be accounted for) and for predators having a large quantity of stomach content material.