Molecular weight conjugation

The ability to select the relative size of the antibody—enzyme complex is important, depending on the assay application. Low-molecular-weight conjugates may be more optimal for immunohistochemical staining or blotting techniques where penetration... 

Dissolve avidin or streptavidin at a concentration of 10 mg/ml in 0.2 M sodium bicarbonate, pH 9.6, at room temperature. The high-pH buffer will result in very efficient Schiff base formation and conjugation with the highest possible incorporation of enzyme molecules per avidin or streptavidin molecule. To produce lower molecular weight conjugates (using less efficient Schiff base formation conditions), dissolve the proteins at a concentration of 10 mg/ml in 0.1 M sodium phosphate, 0.15 M NaCl, pH 7.2. 

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