Whole IgG antibodies are isolated as intact molecules from antisera by immunoaffinity chromatography. They have an Fc portion and two antigen binding Fab portions joined together by disulfide bonds and therefore they are divalent. The average molecular weight is reported to be about 160 kDa. The whole IgG form of antibodies is suitable for the majority of immunodetection procedures and is the most cost effective.
LM Grade colloidal gold reagents are intended for light microscopy and immunoblotting. Since signal intensity is relatively independent of particle size when silver enhancement is used, we offer 4 nm particles because this size may penetrate tissues better than larger particles.
The 4 nm size may be used for electron microscopy in studies that require smaller particles since they are relatively uniform in size (coefficient of variation less than or equal to 15%), though small aggregates are not removed from this grade. Therefore, our 4 nm particles should only be used for electron microscopy with the
understanding that the presence of small aggregates may give misleading results.
A detailed protocol for silver enhancement is provided with all orders for LM Grade products. All reagents involved in the light-insensitive silver enhancement reaction can be prepared easily in the laboratory. However, those who wish to use commercially available silver enhancement kits can continue to do so. All LM Grade colloidal gold-protein complexes are freeze-dried in buffer with stabilizers and a preservative. After reconstitution, they may be frozen in aliquots for extended storage.
This product is for IN VITRO RESEARCH USE ONLY. It is not a medical device and it is not intended for diagnostic or therapeutic purposes.