How to Use
Vector Design Studio
RNA Mass - Moles Converter
Accurately measuring the quantity of your RNA is imperative for a range of molecular biology
applications, including reverse transcription, vector cloning, qRT-PCR, transfection, and IVT RNA production.
VectorBuilder’s RNA calculator allows you to easily retrieve molecular weight and amount of
your RNA (mass or moles) to ensure correct setup of your experiment. (Note: Nucleic acid MW calculations
assume deprotonated phosphate hydroxyl groups.)
Molecular weight calculation
Knowing the molecular weight of your compound is important for biology applications ranging from simple molecular biology processes like gel electrophoresis to clinical drug development. Molecular weight is determined by summing the weights of the protons, neutrons, and electrons in a molecule. To convert between mass and moles of a biomolecule, the molecular weight of a biomolecule must first be obtained. To determine the molecular weight of a strand of RNA, sum the molecular weights of each nucleotide in the RNA sequence. Example calculations are shown below for the RNA base adenosine. Alternatively, if just the sequence length is entered, the average nucleotide molecular weight is multiplied by the length for an approximation.
Figure 1. Chemical structure of adenosine and example calculation of its molecular weight.
Mass - moles converter
In chemistry, a mole represents a quantity of substance containing Avogadro's number of particles (6.02214076 × 1023), typically atoms or molecules. After obtaining the molecular weight of a biomolecule by summing the molecular weights of its components, the mass and moles of a substance can be calculated using the following equation:
Moles RNA (mol) = Mass RNA (g) / Molecular Weight (g/mol)
Figure 2. Equation used to convert between moles and mass of a substance with known molecular weight.
Copy number determination
To calculate the copy number of RNA from the number of moles, multiply the number of moles by Avogadro’s number (6.02214076 × 1023). This calculation is the same for single-stranded and double-stranded molecules as the calculation is based on the number of molecules, not the individual nucleotides.
Copy Number (copies or molecules) = Moles RNA (mol) x 6.022 x 1023 molecules/mol
Figure 3. Equation to determine the copy number for single- and double-stranded RNA.
Moles 3'/5' ends calculation
To calculate the moles of 3' and 5' ends of RNA, it's important to distinguish between single-stranded (ssRNA) and double-stranded RNA (dsRNA). In ssRNA, each molecule has one 3' end and one 5' end, so the moles of 3' ends and 5' ends are equal to the moles of ssRNA present. In contrast, dsRNA consists of two complementary strands, each with a 3' and a 5' end. Therefore, the following equations can be used to determine the moles of 3'/5' ends given that the state of the RNA molecule is known.
Moles 3'/5' Ends (mol) = Moles ssRNA (mol)
Moles 3'/5' Ends (mol) = Moles dsRNA (mol) x 2
Figure 4. Equation to determine the moles of 3'/5' ends for single- and double-stranded RNA.