If the power remained off for 2 hours after 11:45 pm, the tissue would be

• A. overhardened
• B. underfixed
• C. properly embedded
• D. soft

Answer: (A)

Interruption of processing steps, especially those that involve controlled temperatures, can push tissue toward being too dry and brittle. If power is off for two hours, the tissue spends an extended time in dehydrants and clearing solutions without the normal heat, agitation, or timing that keeps dehydration at the proper level. Ethanol and clearing agents continue to extract water and solvents, thinning and stiffening the tissue beyond what the embedding step can accommodate. When finally infiltrated with paraffin, that over-dehydrated tissue tends to be hard and brittle, so the block ends up overhardened.

In contrast, underfixed tissue would be more pliable due to insufficient cross-linking, properly embedded tissue would reflect correct infiltration and support, and soft tissue would result from insufficient dehydration or improper processing—not from a power interruption delaying steps.