Four test methods of HEPA filter such as D.O.P test, sodium flame test, oil mist test and particle counting test,are introduced briefly.Furthermore the numerical relations of the above four methods are analyzed. The differences between efficiency of test and practical efficiency and the aspects needed to be considered when testing filter for bio-protection are discussed at the end.

Objective To construct the UAS-Hey transgenic fly strains to provide a tool for researching the function of Hey gene in the fly development.Methods The Hey gene coding sequence was amplified by reverse transcription PCR and subcloned into pUAST expression vector.The pUAS-Hey recombinant plasmid was constructed and microinjected into the embryos of wild type flies.The UAS-Hey transgenic flies with red eyes were screened out with mini-white marker,then the balancing and mapping of these transgenic strains were performed.The identification was performed by using the PCR amplification method.Results The pUAS-Hey recombinant plasmid was successfully constructed,and seven independent transgenic strains were obtained by microinjection and transgenic fly screening and balance.PCR analysis confirmed that the P[mini-white,UAS-Hey] was integrated into genomes of transgenic strains and was in expressible region.Conclusion The UAS-Hey transgenic flies are successfully constructed,which lays the foundation for further studies of the function and regulation of Hey gene with GAL4/UAS system.