Final answer:
The correct answer for the tissue preservation technique is to place the tissue into cryopreservation media immediately to prevent cellular damage, followed by systematic cooling and storage in liquid nitrogen at -196°C.
Step-by-step explanation:
When handling tissue preparation for cryopreservation, it's critical to protect the viability of the cells. The tissue should not be randomly placed at -40°C or immediately into a sterile or antibiotic solution. Instead, the cells must be placed into cryopreservation media promptly to prevent cellular damage. This media typically contains protective agents like dimethyl sulfoxide (DMSO) or glycerol which facilitate safe freezing and long-term storage in liquid nitrogen at -196°C without crystallization damage to the cells.
The process typically involves cooling the cells to an intermediate temperature like -80°C first before transferring to liquid nitrogen for storage. This methodical cooling is essential to prevent shock and ice crystal formation that can damage cellular structures. It is also crucial that cells are handled with proper aseptic techniques to maintain sterility and prevent contamination. Following these protocols ensures that the cells remain viable and uncontaminated for future use.
Lastly, note that personal protective equipment (PPE) such as gloves should always be worn, and surfaces should be disinfected before and after working with biological samples, to maintain safety and sample integrity.