SummaryWe have used biochemical methods to extend and improve serological class I typing using a panel of 77 Swiss goats of the Saanen breed, comprising dam‐offspring combinations from six half‐sib sire families and several unrelated animals. Of these animals class I molecules were precipitated from cell lysates with the mAb B1.1G6 and HC10. Immunoprecipitates were analysed by SDS‐PAGE and 1D‐IEF. There was a good agreement between class I serological types and IEF banding patterns. We have identified three new class I specificities and subdivided the Bel 7 specificity. IEF has enabled us to make planned immunizations to produce antisera to the new specificities. New evidence for the expression of a second class I locus product in the Be7 haplotype has bee