<P> The stains used are the red coloured Carbol fuchsin that stains the bacteria and a counter stain such as Methylene blue </P> <P> Haematoxylin and eosin staining protocol is used frequently in histology to examine thin sections of tissue . Haematoxylin stains cell nuclei blue, while eosin stains cytoplasm, connective tissue and other extracellular substances pink or red . Eosin is strongly absorbed by red blood cells, colouring them bright red . In a skilfully made H & E preparation the red blood cells are almost orange, and collagen and cytoplasm (especially muscle) acquire different shades of pink . When the staining is done by a machine, the subtle differences in eosinophilia are often lost . Hematoxylin stains the cell nucleus and other acidic structures (such as RNA - rich portions of the cytoplasm and the matrix of hyaline cartilage) blue . In contrast, eosin stains the cytoplasm and collagen pink . </P> <P> Papanicolaou staining, or Pap staining, is a frequently used method for examining cell samples from various bodily secretions . It is frequently used to stain Pap smear specimens . It uses a combination of haematoxylin, Orange G, eosin Y, Light Green SF yellowish, and sometimes Bismarck Brown Y . </P> <P> Periodic acid - Schiff staining is used to mark carbohydrates (glycogen, glycoprotein, proteoglycans). It is used to distinguish different types of glycogen storage diseases . </P>

Types of staining techniques used with light microscopy