Antibody pair screening methods

A method for identifying an antibody pair that selectively interacts with an antigen comprising:

• (a) screening a series of antibody preparations that may react with a target antigen to identify at least two antibody preparations with high affinity for the target antigen, thereby generating at least one first high affinity antibody preparation and at least one second high affinity antibody preparation;
• (b) immobilizing the first high affinity antibody preparation on a substrate, to generate a first immobilized high affinity antibody preparation;
• (c) measuring the cross-reactivity of the first immobilized high affinity antibody preparation with a second high affinity antibody preparation, to obtain a antibody-antibody cross-reactivity value (C);
• (d) measuring the affinity of the first immobilized high affinity antibody preparation and the second high affinity antibody preparation for the target antigen (A) by observing formation of a ternary sandwich complex formed between a first immobilized high affinity antibody preparation, the target antigen, and the second high affinity antibody preparation;
• (e) determining the percent specific activity for formation of the ternary sandwich complex using the following formula:
• [100×(A–C)]/A=% specific activity;
• (f) repeating steps (c)–(e) for each second high affinity antibody preparation;
• (g) repeating steps (b)–(f) for each first high affinity antibody preparation;
• (h) selecting a first high affinity antibody preparation and a second high affinity antibody preparation with the highest percent specific activity as the antibody pair that selectively interacts with the target antigen;
• wherein the same units of measurement are used for C and A.