Which option is outside the cytocentrifuge speed range of 200-1000 rpm?

• A. 100 rpm
• B. 450 rpm
• C. 800 rpm
• D. 1000 rpm

Answer: (A)

Cytocentrifugation relies on operating within a defined speed window so cells sediment properly onto the slide without being damaged. If the speed is too low, cells may not pellet effectively, leading to poor deposition and scattered or incomplete cell monolayers. If the speed is too high, cells can be compressed or distorted, compromising morphology. Within the specified range, speeds near the lower limit still achieve adequate sedimentation, while speeds at or near the upper limit maintain cell integrity.

Among the options, the speed that is well below the lower limit is outside the range because 200 rpm is the minimum. The other speeds fall within the range, with 1000 rpm representing the upper boundary.