Date of Graduation


Document Type


Degree Name

Bachelor of Science

Degree Level



Biomedical Engineering


Muldoon, Timothy

Committee Member/Reader

Quinn, Kyle


Histology often requires a tissue specimen to be embedded so that it may be sectioned, stained, and mounted on a microscope slide for viewing. One common method of tissue embedding for rapid histology is freezing, since freezing allows tissue to be stored without the need for fixing. Frozen tissue is often embedded in a medium such as Optimal Cutting Temperature (OCT) compound so that it can be sectioned using a cryostat. However, factors such as ice-crystal formation during the freezing process can cause damage to the tissue. As such, the protocol used to freeze the tissue can affect the quality of the slides.

The purpose of this project is to compare different freezing methods and examine their strengths and weaknesses when applied to murine colonic tissue. Murine colonic tissue was frozen using two snap-freezing methods, piezoelectric freezing, and two different cold storage methods, each with their own three to four variations. Transverse sections were made in a cryostat, which were mounted on slides and stained using a hematoxylin and eosin (H&E) staining protocol. The sections were then imaged using a light microscope. A blind test was conducted to rate the image quality and inter-rater agreement was calculated using Fleiss’s Kappa. Paraffin embedding obtained the highest score, while OCT embedding inside a -80°C freezer received the second highest score.


Cells, Freezing, Tissue, Histology, Microscopy, Ice