[Purification and physicochemical characterization of allergen I from Dermatophagoides farinae]

Dermatophagoides farinae allergen I (Der f I) has been extracted and purified from spent culture medium of Dermatophagoides farinae by affinity chromatography coupled with anti-Der f I McAb for the first time in China. Furthermore, its physicochemical properties were analysed. By SDS-PAGE, Der f I was estimated to have a molecular weight of 24 kDa and appeared as only one protein band. By isoelectric focusing, it was revealed to have pIs of 4.8-7.5 with six protein bands, suggesting that Der f I is heterogeneous with complicated composition.