Negative staining

Used for contrasting thin specimen with an optically opaque fluid.

■ In this technique, the background is stained, leaving the actual specimen untouched, and thus visible.

■ Negative staining is typically performed using a black ink fluid such as NIGROSIN.

■ Spores appear light against the dark surrounding background.

■ It includes ammonium molybdate, uranyl acetate, uranyl formate, phosphotungstic acid, osmium tetroxide, osmium ferricyanide and auroglucothionate.

■ It is used for -----viruses, bacteria, bacterial flagella,biological membrane structures and proteins or protein aggregates