In operating the centrifuge, opposing tubes must be of equal weights.

• A. True
• B. False
• C. Not important
• D. Sometimes

Answer: (A)

Balancing a centrifuge rotor is essential for safe and effective operation. When opposing tubes have equal weights, the centrifugal forces generated on opposite sides cancel each other, so there is no net sideways force on the rotor. This keeps the rotor spinning smoothly, protects bearings and seals, reduces heat and vibration, and preserves sample integrity. If weights differ, the rotor becomes unbalanced, leading to wobble, mechanical wear, possible rotor failure, and compromised results. You always use a counterweight or match the masses to achieve symmetry. The statement that opposing tubes must be equal in weight is true; treating balance as optional would risk equipment damage and unsafe operation.