Microtitre plates: edge effects?

[Elliott Dawson]

My experience is that "edge effects" are usually caused by temperature 
differences or evaporative loss etc.occurring because of the type of 
incubator, plate seal used,or plate storage conditions.  These effects can, 
of course, occurr not only during the actual performance of the elisa, but 
also during the preparation and storage of the plates.  My experience is 
that an edge effect is most likely to take place in stored plates, where 
moisture intrudes into the outer edges and degrdes the immunological 
reactivity of the material absorbed or bound to the plates.  I have found 
that placing prepared plates sealed with mylar or foil covers into heat 
sealable bags with a silica desicant pack(Sigma and others)and sealing the 
bags has prevented a degradation in signal or increased non-specific binding 
for periods out to ~5 years when stored at RT or 4C(temp depending on the 
specific immunological material absorbed on the plate).