Thermal gradients in microtitration plates. Effects on enzyme-linked immunoassay.

Temperature studies of microtitration plates demonstrate that the use of a common bacteriology incubator for heating the plates can cause a phase log of over 30 min for the fluid in the wells to reach 37 degrees C from ambient temperature, and that a temperature gradient of as much as 1.6 degree C can exist between the peripheral and center wells. This gradient is a cause of the "rim" of edge effect noted in enzyme immunoassay using microtitration plates. The problem is corrected by the use of a specially designed forced air microtitration plate incubator.