Rapid micromethod for preparation of enzyme-antibody conjugates

A rapid method is described for labeling antibody with alkaline phosphatase by one-step glutaraldehyde linkage. The method involves the centrifugation of a small volume of an enzyme and antibody mixture through a minicolumn packed with hydrated Sephadex. This procedure rapidly removes ammonium sulfate and glutaraldehyde from the enzyme-antibody mixture and results in the efficient recovery of conjugated antibody without significant dilution.