Question

PBT is just Phosphate Buffered Saline with Triton X-100. What is Triton X-100 and why might we use it for IHC?

Answer 1

Triton X-100 is a nonionic surfactant that has a hydrophilic polyethylene oxide chain (on average it has 9.5 ethylene oxide units) and an aromatic hydrocarbon lipophilic or hydrophobic group. Triton X-100 is widely used to lyse cells to extract protein or organelles, or to permeabilize the membranes of living cells.

Triton X-100 can dissolve the lipid on cell membranes, nuclear membranes, and organellar membranes, therefore big molecules such as antibodies can get into cytoplasm and nucleus to bind antigens. In immunohistochemistry (IHC) as a detergent, Triton X-100 works with a concentration of 0.5%-1% in PBS buffer.