Resuspension calculator explained
When rehydrating lyophilized oligos, antibodies, or enzymes, you typically know the amount supplied (nmol, mg, or units) and the concentration you need. This calculator divides the provided amount {given} by the desired concentration {desired} to return the diluent volume {volume} required to hit that target.
Use it for primer resuspension, antibody prep, or any SOP that needs precise instructions like "add X µL of buffer to achieve Y mg/mL."
How the conversion works
Simple proportionality:
where is the diluent volume, "amount" is mass, moles, or units in the vial, and is the desired concentration in the same basis. The calculator handles any unit system as long as you keep it consistent.
Units and conversions
| Quantity | Units | Notes |
|---|---|---|
| Amount | nmol, µg, mg, units | Use the figure printed on the vial. |
| Desired concentration | µM, mg/mL, units/µL | Pick what your protocol specifies. |
| Volume | µL or mL | Output telling you how much buffer to add. |
Worked examples
- DNA primer
Vial contains 25 nmol oligo; you want a 100 µM stock.
Add 250 µL nuclease-free water, vortex, then make working dilutions.
- Antibody resuspension
Lyophilized antibody mass is 1.0 mg. Desired concentration is 2.0 mg/mL.
Add 500 µL of the recommended buffer and let the vial sit for 5 minutes before gentle mixing.
Tips and pitfalls
- Warm viscous buffers to room temperature so they pipette accurately.
- Mix gently after adding diluent; avoid foaming proteins or shearing DNA.
- Record both the stock concentration and any secondary dilutions to prevent future math errors.
- If the vendor supplies both "synthesis scale" and "delivered amount," always use the delivered amount for calculations.