New formula to calculate the concentration of an oligo
Eurofins has updated the formula used to determine the oligonucleotide concentration to support you with more accurate values for your applications.
The relationship between the amount of substance, measured OD260 and molar extinction coefficient at 260 nm (ε260) is given as:
nmol = OD260 x 106 / ε260
The molar extinction coefficient is a unique physical property of each oligonucleotide determined by the nucleotide composition.
The ε260 of the oligonucleotide is calculated as the sum of all ε260 values of the nucleotides composing the sequence.
What is new
The formula what Eurofins has always used to calculate the amount of substance is:
nmol = OD x 100 / (1.54 x nA + 0.75 x nC + 1.17 x nG + 0.92 x nT)
Now, Eurofins has also implemented a new formula to make the calculation of the molar extinction coefficient and thus the determination of amount of substance more accurate. The new formula is based on the nearest-neighbor method and takes into account the sequence specific effects.
nmol = OD x 106 / ε260
For your oligos you can decide in your personal preferences which formula should be used to calculate the oligo concentration.
Nearest-neighbor and individual-bases extinction coefficients are used in the nearest-neighbors formula when calculating the final, total extinction coefficient of an oligonucleotide:
New standard primers available for all Sanger services
Since GATC and Eurofins Genomics joined forces, we have offered separate lists of free available standard primers for the GATC and the Eurofins Sanger sequencing services.
Former list of Standard Primers GATC & Standard Primers Eurofins
What is changing
The most frequently used and common standard primers from Eurofins and GATC are now combined.
These newly defined 80 Standard Primers are available for all Sanger sequencing services free of charge: New Standard Primers
Most of the primers are unchanged. Some of them have been replaced, slightly renamed or the sequence has slightly changed.
See details of the changes.
Some of the former standard primers have been discontinued because of insufficient demand. List of discontinued standard primers
Important for ordering
Please use our new Excel templates for uploading your sequencing reactions which can be downloaded on the sequencing order pages.