Patent ID: 6838254

Claim:
A process for the production of (a) an antibody, or (b) an antibody fragment thereof, or (c) a functionalised fragment thereof, wherein the antibody, or antibody fragment or functionalised fragment is capable of binding antigen, is derived from a heavy chain of an immunoglobulin of Camelidae, lacks features for interacting with corresponding light chains, and is devoid of light chains, lacks a C H 1 domain, includes an FR2 of a V H region which has an arginine or cysteine at the position corresponding to position 45 of the V H region of human IgG; which comprises transforming a lower eukaryotic host which is a mould or a yeast with an expressible DNA sequence encoding said antibody or antibody fragment or functionalised fragment, expressing and isolating said antibody, antibody fragment or functionalised fragment, said yeast being selected from the genera Saccharomyces, Kluyveromyces, Hansenula, and Pichia.