Normal Donkey Serum

Normal donkey serums, which are from non-immuned donkey hosts, are lipid extracted to improve clarity, dialyzed against phosphate buffered saline (PBS) containing sodium azide. Normal serum diluted to 5%-20% (v/v) in PBS is strongly recommended as a blocking reagent to reduce background from non-specific binding, or control for most immunoassay applications. Best results are obtained with diluted normal serum from the same host as the labeled antibody, as a separate incubation step before addition of the primary antibody.