plastic section stain

plas·tic sec·tion stain

1. for electron microscopy, a stain (for example, osmic acid, phosphotungistic acid, potassium permanganate) used on thin sections of plastic-embedded tissues, using differential attachment of heavy atoms to various cellular and tissue structures so that electrons will be absorbed and scattered by these structures to produce an image; to achieve differential staining, the stain must penetrate nonwettable plastic embedments;
2. for light microscopy, a stain (for example, alkaline toluidine blue, silver methenamine) used on plastic-embedded tissues to attain higher resolution and more detail than normally possible; semithick (0.5-1.5 mcm) sections are particularly useful in renal pathology, especially in combination with the phase microscope.