Fully automatic biological tissue staining machine shares staining methods

The fully automatic biological tissue staining machine is mainly used in fields such as histology, pathology, biology, etc. to automatically stain paraffin sections, frozen sections, and cells attached to glass slides.

Staining is one of the most important steps in the production of biological microscope slide specimens. First, the selective permeability of the damaged cell membrane is destroyed, and then the biological tissue is immersed in a staining agent to dye a certain part of the tissue cell with a different color or depth from other parts, producing different refractive indices for observation.

The most commonly used methods are hematoxylin and eosin staining. Hematoxylin is an alkaline dye that dyes the cytoplasm and certain structures within the cytoplasm, such as gentian violet solution, to turn chromosomes blue purple, and methyl green combines with DNA to dye mitochondria blue. We call this property that can be stained blue with hematoxylin basophilic. Eosin is an acidic dye that dyes the cytoplasm and intercellular space, such as RNA, in red.

We call this property that can be dyed red by eosin eosinophilic. The depth of staining can reflect the strength of basophilia and acidophilia. If there is a lack of affinity between two dyes, it is referred to as being neutral. Some tissue components can display colors different from those of dyes. When stained with the blue alkaline dye toluidine, the glycosaminoglycan components in the tissue are dyed purple red. This phenomenon of color difference from the dye becomes metachromism.

In addition, silver staining is also more commonly used. When tissue blocks are immersed in silver nitrate solution, some organizational structures can directly reduce silver nitrate, causing silver particles to adhere to them, appearing brownish black or brownish yellow. Some structures themselves have no direct reduction ability for silver nitrate. If a reducing agent is added, the silver nitrate can be reduced and precipitated for color development.