Is it possible to do pre-embedding labeling of intracellular antigens?
Yes. Single cells are most suited. Plant material with a thick impenetrable wall is not. The ultra small gold conjugates are the conjugates of choice. In many cases a permeabilization step with NaBH4 suffices to open up the specimens and allow penetration of reagents. Low concentrations of mild detergents like saponin help. One thing should be emphasized: reaction times have to be prolonged since full penetration of the reagents to the internal antigens has to be achieved. To remove unreacted reagents after incubation wash procedures have to be adapted likewise! The Aurion Newsletter #5 deals with this topic. Please see elsewhere on this site.
