There are two steps involved in this calculation:

- The sample concentration is converted from ng/μl to nM.
- This concentration in nM is used as the starting concentration for a dilution step to obtain a solution at the target concentration

Assumptions: These calculations assume the sample is double stranded DNA and that the average mass of a pair of nucleotide bases is 660 Daltons (Da). This makes the formula weight^{*} of the base pairs in the double stranded DNA 660 g. The inverse of the molecular weight is the number of moles of template present in one gram of material.

**1. Convert ng/μl to nM:**

The conversions factor and other inputs needed to perform these conversions are:

- Concentration in ng/μl (starting point)
- Strand length (in base pairs)
- 1 g = 1×10
^{9} ng
- 1 mole of nucleotide base pairs = 660 g
- 1 L = 1×10
^{9} μl
- 1 M = 1 mole/L
- 1 nM = 1×10
^{-9} M

People with a solid understanding of the relationship between the units of ng/μl and nM can skip some steps, but the most comprehensive set of step between these two units is ng/μl > g/μl > moles/μl> moles/L == M > nM
The complete process looks like this:

**2. Determine the dilution needed using C**_{1}V_{1} = C_{2}V_{2}

where:

- C
_{1} = initial concentration in nM
- V
_{1} = volume to add to dilution (unknown)
- C
_{2} = desired concentration in nM
- V
_{2} = desired volume in μl

solving for V

_{1} creates the following equation:

V_{1} will have the units of μl. It is the volume of the starting solution to add to the dilution. The amount of buffer equals:

μl of buffer to add = desired volume - V_{1}

**Example Solution:**