Antibody Libraries

1 . A composition comprising a plurality of antibody fragments, each comprising a framework region having a murine VH14 heavy chain and a murine VK2 light chain, or homologues thereof, each antibody fragment further comprising at least one different CDR.

2 . A composition according to claim 1 , wherein each framework region consists of a murine VH14 heavy chain and a murine VK2 light chain, or homologues thereof.

3 . A composition according to claim 1 or claim 2 , wherein the framework comprises either of the sequences identified herein as SEQ ID Nos 1 and 2.

4 . A composition according to claim 1 or claim 2 , wherein the homologues are a human VH1B heavy chain and a human VK2 light chain.

5 . A composition according to any preceding claim, wherein each antibody fragment is a single chain Fv fragment or multimer thereof.

6 . A composition according to any preceding claim, wherein the different CDRs differ with respect to each other by the substitution, addition or deletion of at least one amino acid residue.

7 . A composition according to claim 6 , wherein each CDR retains those amino acid residues that stabilise the localised canonical structure of each CDR.

8 . A composition comprising a plurality of nucleic acids encoding a plurality antibody fragments according to any of claims 1 to 7 .

9 . A method for identifying an antibody having affinity for a target molecule, comprising the steps of:

(i) treating the composition according to claim 8 under conditions suitable for gene expression;

(ii) contacting the expressed antibody fragments with a target molecule;

(iii) identifying antibody fragments that bind to the target molecule; and

(iv) optionally, introducing variation into those nucleic acids encoding the identified antibody fragments and repeating steps (i) to (iii) to identify antibody fragments with different binding properties.

10 . A method according to claim 9 , wherein steps (i) to (iii) are carried out by ribosome or phage display or any combination thereof.

11 . A plurality of antibody fragments as defined in claim 1 , immobilised on a support material.

12 . A method of creating a plurality of antibody fragments, each comprising a different binding affinity, comprising the step of mutating at least one CDR within a framework region having a murine VH14 heavy chain and a murine VK2 light chain, or homologues thereof, wherein each antibody fragment comprises a different mutation.