Resuspension Calculator
Find the exact buffer volume to resuspend oligos and primers to any desired concentration. Free resuspension calculator for molecular biology and biochemistry labs.
Enter any two values to calculate the third.
About This Calculator
The Resuspension Calculator helps molecular biologists, biochemists, and lab researchers determine the exact volume of diluent needed to resuspend oligonucleotides (oligos) or primers to a desired concentration. Whether you are preparing stock solutions for PCR, sequencing, gene expression analysis, or other molecular biology applications, this calculator eliminates guesswork and ensures accurate resuspension every time.
The calculator uses the standard resuspension formula: Volume (μL) = Amount of Oligo (nmol) × 1000 / Desired Concentration (μM). Enter any two values among oligo amount, desired concentration, and diluent volume, and the calculator will automatically compute the missing third value. This flexibility lets you determine how much buffer to add to achieve a target concentration, what concentration results from a given volume, or how much oligo is needed for a specific volume and concentration. The conversion factor of 1000 bridges the nanomole and micromolar units, making calculations straightforward for lab use.
This tool is essential for labs working with synthetic oligonucleotides, PCR primers, siRNA, and other short nucleic acid sequences. Proper resuspension ensures uniform distribution of oligonucleotides in solution, which is critical for reproducible experimental results in PCR, sequencing, cloning, and gene expression analysis. The calculator also features an interactive chart showing the relationship between desired concentration and required diluent volume for a fixed oligo amount, helping researchers plan their experiments and choose appropriate resuspension parameters.
Oligonucleotide resuspension is a fundamental step in molecular biology workflows. Synthetic oligos are typically shipped as dried pellets and must be resuspended in nuclease-free water or TE buffer before use. The recommended resuspension concentration varies by application — PCR primers are often resuspended at 100 μM stock concentration, while qPCR probes may require different concentrations. This calculator supports all common resuspension scenarios and helps maintain consistency across experiments.
Frequently Asked Questions
What is resuspension in chemistry?
Resuspension is the process of remixing substances that have settled or sedimented at the bottom of a solution. In chemistry and molecular biology, resuspension involves dissolving or redispersing a pellet (such as oligonucleotides, primers, or cells) in a buffer or diluent to create a homogeneous solution for accurate analysis or use.
How does the oligo resuspension calculator work?
Enter any two values among oligo amount (nmol), desired concentration (μM), and diluent volume (μL). The calculator uses the formula Volume (μL) = Amount (nmol) × 1000 / Concentration (μM) to compute the missing third value automatically. This allows you to determine how much buffer to add, or what concentration you will achieve with a given volume.
What is the formula for calculating resuspension volume?
The resuspension formula is: Required Diluent Volume (μL) = Amount of Oligo (nmol) × 1000 / Desired Concentration (μM). For example, to resuspend 10 nmol of oligo to a concentration of 100 μM, you need 10 × 1000 / 100 = 100 μL of buffer.
What is the difference between oligo resuspension and primer resuspension?
Oligo and primer resuspension both involve dissolving short DNA or RNA sequences in a buffer solution, but they differ in application. Oligo resuspension is used for general oligonucleotides in molecular biology applications like PCR, sequencing, and gene expression analysis. Primer resuspension specifically refers to resuspending PCR primers. The buffer solution is typically TE buffer or nuclease-free water in both cases.
What is a resuspension buffer?
A resuspension buffer is a solution used to resuspend and dissolve biological samples such as cells, DNA, or oligonucleotides. It typically contains salts, detergents, and stabilizing agents that preserve sample integrity and prevent degradation. Common resuspension buffers include TE buffer (Tris-EDTA) for DNA storage and PBS (phosphate-buffered saline) for cell resuspension.
How do I ensure complete resuspension of oligos?
To ensure complete resuspension of oligonucleotides, after adding the calculated volume of buffer, vortex the tube briefly or pipette the mixture up and down several times. For larger oligos or those with complex secondary structures, brief heating to 55-65°C for 5-10 minutes followed by cooling on ice may help achieve full resuspension. Always use nuclease-free water or TE buffer for optimal results.
Can I use the resuspension calculator for cell resuspension?
This calculator is primarily designed for oligonucleotide and primer resuspension using the formula Volume = Amount × 1000 / Concentration. For cell resuspension, the calculation may differ as cell pelleting and resuspension typically involves counting cells and resuspending at a target cells/mL density rather than using molar concentration. However, the same volume calculation principle applies if you know your desired cell concentration.
What units does the resuspension calculator use?
The calculator uses nanomoles (nmol) for oligo amount, micromolar (μM) for desired concentration, and microliters (μL) for diluent volume. These are the standard units used in molecular biology labs for oligonucleotide resuspension. The formula automatically handles the conversion factor of 1000 between these units.