The preparation and testing of the proposed International Reference (IRP) Bermuda grass (Cynodon dactylon)-pollen...

A lyophilized candidate extract of Bermuda-grass (Cynodon dactylon) pollen, intended for use as an International Reference Standard, was prepared by pooling four individual candidate extracts. In preliminary investigations, the four candidate extracts encompassed a variety of extraction methods. The collaborative testing program simultaneously analyzed the proposed reference and the individual extracts and included 11 laboratories performing RAST inhibition, histamine release, crossed immunoelectrophoresis, crossed radioimmunoelectrophoresis, isoelectric focusing, sodium dodecyl sulfate gel electrophoresis, and protein determinations with a variety of reagents and methods. The four candidate extracts and the pooled reference were found to be equivalent. The stability of this extract has also been studied. This International Reference Preparation of Bermuda grass-pollen extract should be useful for research and industry.