Optimising the extraction of allergens in Betula pollen as determined by isoelectric focusing in polyacrylamide gels.

Water soluble proteins extracted from birch pollen are responsible for most of the allergic symptoms in central and northern Europe as well as in parts of northern U.S.A. and Canada. Previous immunological studies of pollen allergens by isoelectric focusing (IEF) in polyacrylamide gels (PAGs) used a variety of extraction methods with little regard to standardisation or optimisation. In the present study a variety of buffers with various pH, charged buffering ions and ionic strengths were evaluated against different extraction times and temperatures in order to determine the optimum conditions for protein extraction. The largest number of proteins, determined by IEF, were found when extractions were performed at 10 degrees C and for 1 hour. Coomassie Blue and silver staining methods were compared.