Antigen binding domains

1. A process for the production of an antigen specific antigen binding domain comprising the steps of:

(a) immunizing a member of the Elasmobranchii subclass with a specific antigen such that the binding domain is somatically matured;

(b) isolating lymphocytes from the immunizing species;

(c) isolating RNA from the lymphocytes;

(d) amplifying DNA sequences encoding the antigen specific antigen binding domain by PCR;

(e) cloning the amplified DNA into a display vector;

(f) transforming a host to produce a library;

(g) selecting the desired clones from the library;

(h) isolating and purifying the antigen specific antigen binding domain from these clones;

(i) cloning the DNA sequences encoding the antigen specific antigen binding domain into an expression vector;

(j) transforming a host with the expression vector;

(k) culturing the host; and

(l) isolating the antigen specific antigen binding domain so that the antigen specific antigen binding domain is produced.

2. A process according to claim 1 wherein the member is a shark or dog fish.

3. A process according to claim 1 wherein before step (d) the cDNA of the antigen specific antigen binding domain is generated.

4. A process according to claim 1 wherein the restriction enzymes are used to digest the amplified DNA sequences encoding the antigen specific antigen binding domain.

5. A process according to claim 4 wherein the restriction enzymes are NcoI and NotI.

6. A process according to claim 1 wherein the display vector is any phagemid vector.

7. A process according to claim 1 wherein the expression vector is a soluble expression vector.

8. A process for the production of an antigen specific antigen binding domain comprising:

(a) transforming a host with an expressible DNA sequence encoding an antigen specific antigen binding domain, wherein the antigen specific antigen binding domain is derived from a variable region of the immunoglobulin isotype Novel Antigen Receptor (NAR) from a member of the Elasmobranchii subclass immunized with a specific antigen;

(b) culturing the host so that the antigen specific antigen binding domain is expressed; and

(c) isolating the antigen specific antigen binding domain, thereby producing an antigen specific antigen binding domain.

9. The process of claim 8 wherein the member is a shark or dog fish.

10. The process of claim 8 wherein the transformed host is a prokaryote or a lower eukaryote.

11. The process of claim 10 wherein the prokaryote host is Escherichia coli.

12. The process of claim 8 wherein the expressible DNA sequence is in the form of a phagemid vector.

13. The process of claim 8 wherein the member is a nurse shark.

14. The process of claim 8 wherein the antigen specific antigen binding domain is specific for the antigen.

15. The process of claim 8 wherein the antigen specific antigen binding domain is monoclonal.