ObjectiveTo prepare and identify polyclonal antibodies against secretory aspartyl proteinase 2(Sap2) of Candida albicans.MethodsCandida albicans genomic DNA was extracted as template, target gene fragment SAP2 was obtained by standard PCR amplification; SAP2 and plasmids pMALc2x (+) were cleaved with two restriction endonucleases,and digested products were joined,then the recombinant plasmid pMALc2x/SAP2 was constructed; Sap2 was expressed as soluble form after induced by IPTG in Escherichia coli strain BL21 (DE3). Nine BALB/c mice were immunized with soluble Sap2,so as to produce antiserum against Sap2.The titer of antiserum was determined by indirect enzymelinked immunosorbent assay(ELISA). After purified by ProteinG affinity chromatography, antiSap2 polyclonal antibody was resolved by SDSPAGE and its specificity was determined by Western Blot.ResultsAntiSap2 polyclonal antibody was successfully prepared and the titer was >1∶51 200. The antibody could specifically recognize Sap2 by Western Blot analysis. ConclusionSoluble Sap2 protein can be used as antigen to immunize animal. It has better antigenicity and immunogenicity. Polyclonal antibody against Sap2 can be prepared by animal immunization and expressed high specificity, which has laid the foundation for development of rapid diagnosis of invasive Candida albicans infection.