Isolation and characterization of the allergen Dpt 12 from Dermatophagoides pteronyssinus by chromatofocusing.

The allergen Dpt 12, from the house dust mite Dermatophagoides pteronyssinus, was isolated from spent growth medium by chromatofocusing. The allergen was isolated in the pI range 5.86-6.95, indicating heterogeneity with regard to pI. However, on sodium dodecylsulphate-polyacrylamide gel electrophoresis the allergen appeared homogeneous with an apparent molecular weight of 27,000 daltons. Radioallergosorbent scores utilizing paper discs coupled with Dpt 12 correlated significantly (p less than 0.0005) with those obtained using discs coupled with whole mite extract, although the corresponding titres were higher with Dpt 12 (p less than 0.0005).