How It Works
This calculator works in 3 steps.
Enter the nmol amount
Type the yield from the tube label or specification sheet.
Enter the target concentration
Type the stock strength in µM, such as 100 µM.
Read the buffer volume
The calculator returns µL of TE or water to add.
Mix and rest
Vortex briefly, spin down, and let the oligo dissolve for a few minutes before use.
The Formula
The formula divides the nmol amount by the target concentration in µM and multiplies by 1,000.
V (µL) = nmol × 1,000 / C (µM)V (µL) = nmol × 10C (µM) = nmol × 1,000 / V (µL)- nmol:
- Oligo amount supplied
- C:
- Target stock concentration (µM)
- V:
- Buffer volume (µL)
A tube with 37.4 nmol reconstituted to 100 µM needs 374 µL of TE buffer.
Conversion Table
The conversion table gives buffer volumes for 100 µM, 10 µM, and 1 mM stocks for 6 oligo yields.
| Yield | Volume for 100 µM | Volume for 10 µM | Volume for 1 mM |
|---|---|---|---|
| 5 nmol | 50 µL | 500 µL | 5 µL |
| 10 nmol | 100 µL | 1,000 µL | 10 µL |
| 25 nmol | 250 µL | 2,500 µL | 25 µL |
| 37.4 nmol | 374 µL | 3,740 µL | 37.4 µL |
| 50 nmol | 500 µL | 5,000 µL | 50 µL |
| 100 nmol | 1,000 µL | 10,000 µL | 100 µL |
What Is the Oligonucleotide Reconstitution Calculator?
The Oligonucleotide Reconstitution Calculator is a tool that converts the supplied amount of a dried oligo, stated in nmol on the tube, into the buffer volume for a chosen stock concentration. For a 100 µM stock, the buffer volume in µL equals the nmol amount multiplied by 10.
Synthesis yield varies, so suppliers report the exact nmol per tube, such as 37.4 nmol. The calculator uses that exact value rather than the ordered synthesis scale. TE buffer at pH 8.0 or 10 mM Tris is the usual diluent, and the calculator reminds the user to spin the tube before opening.
Common Uses
There are 5 main uses of this calculator.
PCR primer stocks
Users make 100 µM master stocks of new primers.
qPCR probe stocks
Labs reconstitute dual-labeled probes.
siRNA duplexes
Researchers reconstitute siRNA to 20 µM or 50 µM.
Sequencing adapters
Library labs reconstitute adapter oligos.
CRISPR guides
Users reconstitute synthetic sgRNA or crRNA.