Trial to Define the Benefits and Harms of Deceased Donor Kidney Procurement Biopsies

Frozen sections are prepared by freezing and slicing the tissue sample; importantly, they can be done in about 15 to 20 minutes. Frozen sections are done when an immediate answer is needed, but do not provide optimal quality.

Permanent sections are prepared by placing the tissue in fixative (usually formalin) to preserve the tissue, processing it through additional solutions, and then placing it in paraffin wax. After the wax has hardened, the tissue is cut into very thin slices, which are placed on slides and stained. The process normally takes several days.