Nucleic acid conversion data |
1. Determining the copy number of a template (dsDNA) where n is the copy number; c is the concentration vs quantity in µg; m is the molecular weight (MW) of the molecule in Da. Example: 1 kb ds linear DNA molecule has approximate MW of 6,49 · 10 ^{5} Da. 1 µg of this molecule equal to 9,2 · 10 ^{11} copies. 2. Determining the molecular weight of an deoxyoligonucleotide (ssDNA) m = (ndG · 328,2 + ndA · 312,2 + ndT · 303,2 + ndC · 288.2) + (mi · nbp) + (m5'end + m3'end), where m is the molecular weight (MW) of the molecule in Da; n is the number of a corresponding base in the oligonucleotide; mi is the molecular weight (MW) of the counter ion; nbp is the length of the oligonucleotide; m5'end and m3'end are the atom masses at the 5' and 3' ends of the oligonucleotide respectively. Add (17 + 2 · mi) for phosphorylated oligonucleotides and substract (61 + mi) for dephosphorylated oligonucleotides. No phosphate is present at the 5´ end of strands made by primer extension. The atomic masses of the most common oligonucleotide counter-ions are: Na (23), K (39,1), Li (6,9) Example: The oligonucleotide dGdAdAdTdTdCdCdGdAdTdCdGdAdTdCdT (Na salt) has an approximate MW of 5270,2^{} Da. The molar mass of dsDNA can be calculated by doubling the molecular masses of both strands. Approximate molecular mass of a bp in DNA is 649 Da. 3. Determining the molecular weight of an ribooligonucleotide (RNA) m = (nrG · 344,2 + nrA · 328,2 + nrU · 305,2 + nrC · 304.2) + 159, where m is the molecular weight (MW) of the molecule in Da; n is the number of a corresponding base in the oligonucleotide; mi is the molecular weight (MW) of the counter ion. Addition of 159 to the MW takes into account the MW of a 5´ tri-phosphate. Example: The oligonucleotide GAAUUCCGAUCGAUCU has an approximate MW of 5088,2^{} Da. The molar mass of RNA can be calculated using following formula: average mass of a ribonucleotide base x number of bases. Approximate molecular mass of the ribonucleotide is 340,5 Da. |
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