Patent ID: 8883150

Claim:
A method for obtaining nucleic acid encoding a heavy chain-only antibody chain comprising: a) obtaining long-lived plasma cells or memory B-cells from a transgenic mammal including a heavy chain-only locus comprising human VH gene segments, one or more human D gene segments, human J gene segments, and at least one mouse constant region gene segment wherein the human VH gene segments consist of VH1-69, VH4-59, VH3-53, VH3-49, VH4-34, VH3-48, VH3-33, VH3-30, VH3-23, VH1-18, VH3-15, VH4-39, VH1-8, VH3-07, VH2-5, VH4-4, VH1-2, and VH6-1, the human D gene segments comprise at least 20 human D gene segments, the human J gene segments comprise all six human J gene segments, and the mouse constant region gene segment comprises a Cγ lacking CH1, which mammal has been challenged with an antigen; and b) isolating nucleic acid encoding a heavy chain-only antibody chain specific for the antigen from the long-lived plasma cells or memory B-cells.