DNA Molecular Weight Calculator

Select Sequence Type:
Molecular

Results

Base Composition:
Total Length:
GC Ratio:
Molecular Weight:
Accurate DNA quantification is critical for a wide range of molecular biology applications; determining the molecular weight of DNA samples is indispensable for PCR, gel electrophoresis, and vector construction.
How to calculate the concentration of oligonucleotides?
The packaging provided by MCE indicates the oligonucleotide content (net weight) as measured by ultraviolet spectrophotometry (UV-Vis), which is often inconsistent with the weighed weight (gross weight). It means 1 mg refers to 1 mg of oligonucleotides (free acid, net weight). We recommend that you do not weigh and aliquot the powder after receiving the product. Instead, completely dissolve the powder in the vial and then calculate the oligonucleotide concentration based on the oligonucleotide content and purity information:
Concentration (mol/L) = Net weight (g) ÷ MW (g/mol) (MW represents molecular weight (free acid)) ÷ Volume (L) × Purity
Concentration (g/L) = Net weight (g) ÷ Volume (L) × Purity
What method is used to synthesize oligonucleotides?
The phosphoramidite method is the method of choice for oligonucleotide synthesis. Phosphoramidite oligo synthesis proceeds in the 3'- to 5'-direction (opposite to the 5'- to 3'-direction of DNA biosynthesis in DNA replication).
How to prepare an oligonucleotide stock solution?
Oligonucleotide products supplied by MCE are provided in lyophilized (freeze-dried) form. The lyophilized material may present as a visible powder or as a transparent film, gelatinous mass, or flaky precipitate that is barely discernible to the unaided eye. Furthermore, during transit, lyophilized particles may disperse and adhere to the interior walls of the vial and the underside of the cap, rendering them difficult to detect by visual inspection. Prior to resuspension, perform a brief centrifugation to pellet the contents at the bottom of the vial. Reconstitute the oligonucleotide in a suitable buffer (such as sterile water or nuclease-free water) to generate a stock solution. Divide the solution into aliquots and store at -80°C, avoiding repeated freeze-thaw cycles. Fluorescently labeled oligonucleotides must be protected from light during both handling and storage.