Arrays

A method of simultaneously quantifying the relative functional properties of members of a set of protein moieties which are variants of a protein that differ in their amino acid sequences at one or more positions, the protein moieties of the set of protein moieties being encoded by naturally-occurring variants of a DNA sequence of interest that map to a common chromosomal locus;

• the method comprising the steps of:
• a) obtaining two or more replicate protein arrays, each array comprising a surface on which the protein moieties of the set of protein moieties are deposited at spatially defined locations, and bringing each array into contact with a test substance in solution at a known concentration, where the concentration of the test substance in solution that is applied to at least one of the two or more replicate arrays is different from the concentration of the test substance in solution that is applied to at least one other of the two or more replicate arrays;
• b) measuring the interaction of the test substance with the protein moieties on each array at each known concentration of the test substance;
• and
• c) quantifying the affinity of the interaction of said test substance with each one of the protein moieties;
• wherein the protein moieties of the set of protein moieties are immobilized on the surface by attachment to the surface through a common marker moiety appended to each of the protein moieties of the set of protein moieties;
• wherein the protein moieties of the set of protein moieties are attached to the surface through the common marker moiety such that the protein moieties have their naturally occurring function and/or activity;
• and
• wherein the surface is coated with a porous or non-porous chemical surface coating that is capable of resisting non-specific protein absorption.