1. What is RCF (Relative Centrifugal Force)?

Relative Centrifugal Force (RCF), also known as g-force, is the measurement of the acceleration applied to a sample in a centrifuge. It provides a standardized way to compare centrifugation protocols across different equipment and rotor sizes.

2. How Does the Calculator Work?

The calculator uses the RCF formula:

Where:

• \( RCF \) — Relative centrifugal force (g)
• \( r \) — Rotor radius in centimeters (cm)
• \( RPM \) — Rotations per minute (rev/min)
• \( 1.118 \times 10^{-5} \) — Conversion constant

Explanation: The formula converts rotational speed (RPM) to actual gravitational force experienced by samples, accounting for the rotor's radius and the square of the rotational speed.

3. Importance of RCF Calculation

Details: Accurate RCF calculation is essential for reproducible centrifugation protocols, ensuring consistent separation results across different centrifuges and laboratories. It allows researchers to precisely control sedimentation rates and optimize separation efficiency.

4. Using the Calculator

Tips: Enter the centrifuge's RPM (rotations per minute) and the rotor radius in centimeters. The radius is typically measured from the center of the rotor to the sample position. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why use RCF instead of RPM?
A: RCF provides a standardized measurement of centrifugal force that accounts for rotor size, allowing for reproducible results across different centrifuges, while RPM alone does not consider rotor geometry.

Q2: What is the typical range of RCF values?
A: RCF values range from a few hundred g for gentle separations to over 100,000 g for high-speed ultracentrifugation, depending on the application and equipment.

Q3: How do I measure rotor radius?
A: Measure from the center of the rotor shaft to the middle of the sample tube when it's in the operating position. Consult your centrifuge manual for specific measurements.

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: Are there limitations to this calculation?
A: The calculation assumes ideal conditions and may not account for factors like tube angle, sample density, or acceleration/deceleration profiles. Always verify with manufacturer specifications for critical applications.