BIO 202 Study Guide - Midterm Guide: Immunohistochemistry, Toluidine, Transmission Electron Microscopy
Document Summary
In fixed tissue, h&e stains structures according to their net charge at the ph of the staining solution. The advantages of h&e is that it distinguished cytoplasm from the nucleus very well. Developed to stain collagen some distinctive color to distinguish is from cell cytoplasm. Usually involves using 3 or more stains. Commonly used: mason trichrome (stains collagen greenish blue) and mallory. Areolar tissue: h&e high mag: x40 obj. lens. Xylene (organic solvent) washes the lipids away. Lipids are replaced by paraffin that don t take up the stain. Toluidine blue: counter stain for plastic embedding. You are able to visualize sub cellular structures. Typically stained with lead/uranium salts which are electron dense. The electron dense structures take up more of the lead/uranium (darker pts) Samples are not cut into small sections. Sem is a replica of the tissue (hard metal sheet) After fixation, the tissue is coated with heavy metal atoms such as gold (sputtering)
