The present invention relates to methods for coupling labels to particular
target moieties. The coupling reactions of the present invention use
temporal spacing of the reactants through phase change (i.e. by rapid
freezing) to control the initiation and termination of reaction. This
process results in a simplified and improved method for linking labels to
specific binding moieties using N-hydroxysuccinimide chemistry. The
present invention further relates to kits comprising all necessary
components to easily and rapidly make protein conjugates.