Flashcards

Untitled

Aashka Bahal English 4 cards

Cards in this deck (4)

1LIGHT MICROSCOPE- A beam of visible light is concentrated onto a plane of a tissue section by a condenser lens.
-The light as it passes through the fine structural details of the specimen is refracted by the objective lens forming a magnified image.
-A segmant of the image is magnified by the eyepiece and presented to the eye.
-Resolution of the best LM is abotu 0.2 um.
-Paraffin embedded sections are used, cut by a microtome at 5-8um, with optimum resolution of 0.6um.
-To get better resolution thinner resin embedded sections can be used, at 0.5-2um thickness (semi thin sections).
-Epoxy resin sections are cut using a special microtome, and stained using toluidine blue which is one of the few dyes which can penetrate the hard epoxy resin to stain the tissue section.
2nucleic Basic dyes defintionBind to acidic structures- chromatin in nucleus, ergastoplasm, ground substance in cartilage.
3Types of nucleic basic dyes1_ hematoxylin- different variets due to oxidation and adding of mordants. Stains nuclei dark.
2) basic aniline dyes- cresyl violet and toluidine blue- dyes ergastoplasm different shade (metachromatically) to nucleus eg in nervous system, dyes nuclei greenish blue and nissl substance red.
3)nuclear red- dyes nuclei red.
4—