Custom DNA Oligos


 (553 Kb PDF)

Sigma is pleased to offer OligoEvaluator, our online oligonucleotide sequence calculator.


Modules Features
Analysis Enter your sequence, and the tool returns values for all major physical properties, such as molecular weight and melting temperature
Resuspension Enter the quantity and desired concentration, and the tool returns the volume of water or buffer needed to resuspend a dry oligo
Dilution Enter the stock (resuspension) concentration, desired final volume, and desired final concentration, and the tool returns the volume of stock solution needed for dilution

Advanced Features

Feature Description
Adjustable Reaction Conditions Adjust conditions such as oligonucleotide concentration and the temperature for free energy calculation (affects primer dimer and hairpin searches only)
Secondary Structure Search Fold the sequence to check for primer dimers and hairpins. Calculated free energies are scored as follows: None (0 or no primer dimers/hairpins), Very Weak (-1 to -2 kcal/mol), Weak (-3 to -4 kcal/mol), Moderate (-5 to -6 kcal/mol), Strong (-7 to -9 kcal/mol), and Very Strong (less than -9 kcal/mol)
BLAST Search Check for oligonucleotide sequence homology

OligoEvaluator is easy to use: register or login, select DNA or RNA, paste your sequence, and click calculate. If you wish to adjust the reaction conditions, download the glossary of parameters (553 Kb PDF) to learn more about how the adjustable parameters affect primer dimer and hairpins searches.

All reported properties are available for export to a convenient Excel template.

Your OligoArchitect™ login can be used for OligoEvaluator.