New standard primers available for all Sanger services
Introduction
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.
New formula to calculate the extinction coefficent of an oligo
Introduction
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 changing
The original formula what Eurofins has used to calculate the amount of substance was:
nmol = OD x 100 / (1.54 x nA + 0.75 x nC + 1.17 x nG + 0.92 x nT)
(
Now, Eurofins decided to implement the nearest-neighbor approach in all relevant systems. The aim of the implementation is to make the calculation of the molar extinction coefficient and thus the determination of amount of substance more accurate:
nmol = OD x 106 / ε260
Nearest-neighbor formula
Nearest-neighbor and individual-bases extinction coefficients are used in the nearest-neighbors formula when calculating the final, total extinction coefficient of an oligonucleotide:
This change mainly affects primers and probes for established qPCR assays with a length of 15 to 35 bases. The EC of those oligos is approx. 10 % less.