AURION BSA-c™ is a buffer additive that helps prevent immunodetection reagents (i.e. primary antibodies and secondary reagents) from binding nonspecifically to charged moieties within the specimen. Thus, it suppresses background competitively with little or no effect on the specific reaction. Its successful application is not limited to immunogold detections but it is equally efficient in fluorescent and enzyme-based detection systems. AURION BSA-c™ concentrations as low as 0.01-0.1% inhibit binding of gold conjugate to polycationic poly-l-lysine coated grids almost completely (>99%).
- To suppress residual aldehyde activity
- To saturate multipoint hydrophobic moieties and positive charges with high molecular weight compounds such as those present in the AURION Blocking Solutions
- To reduce non-specific binding of immunoreagents caused by hydrophilic interaction with competing molecules in the incubation and washing solution.
The surface properties of the specimen can be simplified by division into four compartments:
- negatively charged (polyanions, proteins, especially after aldehyde fixation, lipids);
+ positively charged (histone proteins, polycations) and
H hydrophobic (lipids, fat droplets, resins). After an appropriate blocking step these areas are covered with blocking compounds.