CHORIOALLANTOIC MEMBRANE (CAM) ASSAY FOR IDENTIFYING AGENTS WITH BIOLOGICAL EFFECTS

摘要

Novel assays and, particularly, novel chorioallantoic membrane (CAM) assays are disclosed for identifying and/or assessing agents with biological effects (eg agents which effect angiogenesis, or promote neurogenesis, or which are capable of silencing a particular gene(s)), and for assessing toxicity of various agents (eg for toxicity testing of candidate agents with desirable biological effects). The novel CAM assay comprises the steps of: (i) separately placing 2-4 day old embryos from chicken or the like, which have been removed from their shells, into separate cup means to support said embryos through steps (ii) to (vii), wherein each cup means also contains a suitable amount of a growth medium, (ii) incubating said embryos for about 24 hours, (iii) measuring the size of the chorioallantoic membrane (CAM) developed from each embryo, and grouping said embryos having CAMs of substantially similar size, (iv) applying to one or more embryo(s) within a selected group, a candidate agent, wherein said candidate agent is applied to the/each embryo by absorbing the candidate agent onto a porous or otherwise sorbent support and placing said support into contact with the CAM such that at least a portion of the candidate agent thereafter diffuses from said support to the CAM, (v) incubating the embryo(s) of step (iv) and a control embryo(s) from the same selected group for about 18 to 24 hours, (vi) administering to the CAM of each embryo of step (v) a contrasting composition comprising skim milk or the like and a suitably coloured dyestuff, and (vii) determining whether said candidate agent effects the CAM and/or embryo by observing differences between the CAM(s) and/or embryo(s) to which the candidate agent was applied and the CAM(s) and/or embryo(s) of the control embryo(s) of the same selected group.