Paraffin Sections

Assessing the complex vasculature of the labyrinth later in gestation usually is facilitated by using thinner sections.

Paraffin sections. Paraffin sections are more physically stable and superior to frozen sections in maintaining tissue morphology with less damage. Place paraffin ribbon in water bath at about 40 45 º c. Transfer the sections onto a superfrost plus slide.

Trim paraffin blocks as necessary and cut at 3 10 um 5 um is commonly used. Paraffin wax does not provide a sufficiently hard matrix for cutting thinner slices needed for electron microscopy typically 80 100 nm thick. Liquid paraffin section prepare the first portion of liquid paraffin in a suitable bath and allow the paraffin to reach and maintain at 60 c immerse the tissue 2x into the paraffin bath 2 hrs each prepare the second portion of liquid paraffin in a suitable bath and allow the paraffin to reach and maintain at 60 c.

Deparaffinization and re hydration of tissue slide. Section paraffin blocks at the desired thickness usually 4 5 µm on a microtome and float on a 40 c water bath containing distilled water. This tissue is then embedded in wax before being cut on a microtome.

Here epoxy or acrylic resins especially for immunohistochemistry are used. Mount sections onto slides. Allow the slides to dry overnight and store slides at room temperature until ready for use.

Paraffin sections for light microscopy are typically 5 μm thick.