The mini-RAST: Comparison with other varieties of the radioallergosorbent test for the measurement of immunoglobulin E antibodies.

In the performance of the RAST a variety of different solid-phase supports for allergens are utilized. In this study we coupled allergens to microcrystalline cellulose and reduced the quantities of solid-phase allergen tenfold and of anti-IgE fourfold. These reductions actually increased the sensitivity of the RAST for IgE antibodies to several allergens, including those derived from Alternaria tenuis and rye grass pollen. We have termed this procedure the mini-RAST to distinguish it from the procedure employing larger quantities of solid-phase allergen and anti-IgE, the maxi-RAST. We then compared three RAST procedures for the detection of IgE antibodies to ragweed allergens: the maxi-RAST, the mini-RAST, and the paper disk RAST, using both commercial paper disks and disks prepared in our laboratory. The maxi-RAST and the mini-RAST yielded similar results and both appeared more sensitive than the paper disk RAST for the detection of IgE antibodies to ragweed. The results indicate that the microcrystalline cellulose RAST can be significantly scaled down without a loss of its ability to detect IgE antibodies and with a considerable saving of valuable solid-phase allergens and anti-IgE.