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DNA / RNA copy number

Use forward mode to get copies from input mass, or reverse mode to get the required mass for a target copies/µL and final volume. Length is bp for DNA or nt for RNA.

ModeMass → copiesTarget copies/µL → required mass Molecule typedsDNA (660 g/mol·bp)ssDNA (330 g/mol·nt)RNA (340 g/mol·nt) Length (bp or nt)

Input mass Mass unitpgngµgmg Volume (µL, optional)

Target concentration (copies/µL) Final volume (µL) Required mass unitpgngµgmg

Formula: copies = mass(g) ÷ (length × average molecular weight) × 6.022×10²³. Reverse mode uses required mass = target copies ÷ 6.022×10²³ × length × average MW. Very small required masses may be below reliable pipetting or quantification; prepare a measured stock and dilute instead of chasing an unreadably small mass. To turn that stock into a working solution, use Dilution & copy number.