<prompt> All of the following stains are used for fat except?Oil red OCongo redsSudan blackOsmium tetroxide  <response>: Ans. is b i.e., Congo red Congo red is not used in lipid staining. It is used in the staining of amyloid protein. Stain used for lipids fatty acidsare Oil red O, Osmium tetroxide, sudan black and sudan III IV. 