Final answer:
Short term storage of frozen tissue is defined as 12 months or less at -40°C. Option a.
Step-by-step explanation:
Short term storage of frozen tissue is defined as option a, which is 12 months or less at -40°C. Bacterial cultures and medical specimens are often stored at ultra-low temperatures, such as -70 °C or lower, for long-term storage or transport. Freezing tissue with glycerol and storing it at -196°C in liquid nitrogen is also a common method of long-term storage.
In this case, there is no clear industry-standard definition in the provided context. Therefore, based on the available options in the question, there is not enough information to determine the correct answer definitively for short-term storage of frozen tissue. If considering general guidelines for storage temperatures, materials can be stored at -20°C for certain durations as part of short-term storage, while temperatures of -40°C are more common for longer-term storage. However, the duration for standard short-term storage at specific temperatures such as -20°C or -40°C is not stated in the provided material. For accurate scientific practice, always refer to specific protocols and manufacturer guidelines concerning the storage of particular biological materials.