Question

In order to maintain optimal cellular viability, skin grafts may be maintained prior to freezing:

a. In sterile water
b. In tissue culture media at 1 °C to 10 °C
c. At 25 °C
d. Indefinitely at 4 °C

Answer 1

Skin grafts should be maintained in tissue culture media at 1 °C to 10 °C before cryopreservation to ensure short-term temperature stability. Controlled cooling and cryoprotective mediums are then used to protect cells from damage during freezing and long-term storage.

Step-by-step explanation:

In order to maintain optimal cellular viability, skin grafts may be maintained in tissue culture media at temperatures between 1 °C to 10 °C prior to freezing. This range provides the necessary short-term temperature stability for cells before they undergo the freeze-thaw cycle. During cryopreservation, it's standard to employ methods and mediums that protect the cells, such as the use of dimethyl sulfoxide or glycerol combined with controlled cooling rates before storing them at ultra-low temperatures.

Proper cryopreservation is essential because when water in cells freezes, it expands significantly, potentially causing up to 30% of the biological cells to burst due to the formation of ice crystals. To avoid this, cells are often suspended in a cryoprotective medium and frozen at a controlled rate before being stored at temperatures such as -196°C in liquid nitrogen tanks, ensuring long-term storage and post-preparative stability.