Free centrifuge timer for lab procedures. Time microcentrifuge spins, blood separation, and cell pellet preparation. Works alongside centrifuge RPM settings.
Cell pelleting (1000–2000 × g): 5–10 minutes. Protein precipitation (10,000–15,000 × g): 5–15 minutes. Maximum speed spins for pelleting (16,000 × g): 10–30 minutes. Serum/plasma separation (1000–2000 × g): 10 minutes. Always follow the specific protocol for your application.
Over-spinning can: pellet contaminants that should remain in the supernatant, shear DNA or denature proteins in sensitive preparations, and break down red blood cells (haemolysis) in blood separation. Most common centrifuge errors are under-spinning (incomplete separation) rather than over-spinning.
RCF (×g) = 1.118 × 10⁻⁵ × r × RPM². Where r = rotor radius in centimetres. Most protocols specify RCF (×g) rather than RPM, as RCF is rotor-independent. Many centrifuges display both, or provide conversion charts. Always use RCF when following published protocols.
Unbalanced rotors create vibration and stress that can damage the centrifuge bearings, cause catastrophic rotor failure (disintegration at speed), and affect separation quality. Always load opposite tubes with equal volume and weight. For odd numbers, add a water-filled balance tube.
Only with a stable rotor, proper balancing, and within manufacturer specifications. The timer allows you to leave during the spin and return when the alarm sounds. Do not leave centrifuges running unattended overnight in academic settings without appropriate risk assessment and institutional approval.