Is the IEMA combined incubator/shaker device preferable to a waterbath for incubating enzyme immunoassays?

An incubator/shaker device proved to be a convenient alternative to a waterbath for the incubation of enzyme immunoassays (EIA). The device achieved effective and even heat transfer. In two of five EIAs it increased reactivity and in three of five EIAs it slightly increased the discrimination between seronegative and seropositive specimens though, for the samples investigated, extra sensitivity was not thereby achieved. At a high shaking frequency (1400 rpm) there was cross-contamination between wells, but this did not occur at 900 rpm. The relative contributions of heating and of shaking to the incubation of EIAs deserve further investigation.