1. What is RNA Copy Number?

RNA copy number represents the number of RNA molecules in a given volume, calculated from concentration and length. It's essential for quantitative molecular biology experiments like qPCR and RNA sequencing.

2. How Does the Calculator Work?

The calculator uses the RNA copy number equation:

Where:

• \( CN \) — Copy number (dimensionless)
• \( C \) — Concentration (ng/μL)
• \( L \) — Length (nucleotides)
• 6.022 × 10²³ — Avogadro's number
• 340 — Average molecular weight per nucleotide (g/mol)

Explanation: The equation converts mass concentration to molar concentration, then calculates the number of molecules using Avogadro's number.

3. Importance of Copy Number Calculation

Details: Accurate copy number estimation is crucial for experimental standardization, particularly in quantitative PCR, RNA-seq library preparation, and viral load quantification.

4. Using the Calculator

Tips: Enter concentration in ng/μL and length in nucleotides. Both values must be positive numbers. The result represents the number of RNA molecules per microliter.

5. Frequently Asked Questions (FAQ)

Q1: Why is 340 used in the denominator?
A: 340 represents the average molecular weight of a single RNA nucleotide (in g/mol), accounting for the different nucleotide compositions.

Q2: Can this be used for DNA copy number?
A: Yes, but use 330 g/mol for DNA (slightly lower due to absence of uracil's hydroxyl group).

Q3: What if my RNA is double-stranded?
A: For dsRNA, double the length value in the calculation since you have two strands per molecule.

Q4: How accurate is this calculation?
A: It provides a theoretical estimate. Actual values may vary slightly due to nucleotide composition and RNA secondary structure.

Q5: What concentration range is typical?
A: For qPCR standards, typical working concentrations range from 10⁶ to 10¹⁰ copies/μL.