Allergen extracts are prepared from a wide variety of source materials
including pollens, fungi, arthropods, animal danders, foods, and dust
s. The composition of allergen extracts can vary depending on the alle
rgen source, manufacturing process, and storage conditions. Allergen-s
pecific immunoglobulin E (IgE) assays and skin tests employ a variety
of allergen-containing reagents that confer specificity on the test. G
iven that the allergen source materials are heterogenous mixtures of p
roteins, glycoproteins, carbohydrates, and other substances that are n
ot allergenic, it is not unexpected that variability exists between te
st results obtained with different allergen-containing reagents. Varia
bility within a single manufacturer's allergen product can be controll
ed by using reproducible extraction and processing procedures, single
large lots of allergen source materials, and solid-phase supports. The
se controls do not, however, ensure the consistency of products betwee
n manufacturers or laboratories because allergen source materials, man
ufacturing procedures, and acceptance criteria for allergen reagents m
ay vary. (C) 1997 Academic Press.