1. What is RCF vs RPM?

RCF (Relative Centrifugal Force) and RPM (Revolutions Per Minute) are two different ways to express centrifugation speed. RCF represents the actual gravitational force experienced by samples, while RPM indicates the rotational speed of the centrifuge rotor.

2. How Does the Calculator Work?

The calculator uses the RCF formula:

Where:

• \( RCF \) — Relative Centrifugal Force (g)
• \( r \) — Radius from center of rotation to sample (cm)
• \( RPM \) — Revolutions per minute (rev/min)
• \( 1.118 \times 10^{-5} \) — Conversion constant

Explanation: The formula converts rotational speed (RPM) to actual gravitational force (RCF) taking into account the radius of rotation.

3. Importance of RCF Calculation

Details: Accurate RCF calculation is crucial for reproducible experimental results in centrifugation procedures. Different protocols specify RCF rather than RPM because RCF accounts for rotor size variations.

4. Using the Calculator

Tips: Enter radius in centimeters and RPM in revolutions per minute. Both values must be positive numbers. The radius is measured from the center of rotation to the sample position.

5. Frequently Asked Questions (FAQ)

Q1: Why use RCF instead of RPM?
A: RCF provides consistent results across different centrifuges and rotors, while RPM alone doesn't account for rotor radius differences.

Q2: How do I measure the radius?
A: Measure from the center of the centrifuge rotor to the middle of the sample tube when it's in the horizontal position.

Q3: What are typical RCF values used in laboratories?
A: RCF values range from 200-20,000g depending on the application - low speed for cell pelleting, high speed for protein precipitation.

Q4: Can I convert RCF back to RPM?
A: Yes, the formula can be rearranged: \( RPM = \sqrt{\frac{RCF}{1.118 \times 10^{-5} \times r}} \)

Q5: Does temperature affect RCF calculation?
A: No, RCF calculation is independent of temperature, but temperature control is important for many biological samples during centrifugation.