System and method for isolation and qualification of nucleic acids

A method comprising:

• (a) isolating DNA from a source, thereby providing a composition comprising the isolated DNA, wherein the isolated DNA has at least a first target region having a first length in nucleotides and a second target region having a second length in nucleotides, wherein the second length is greater than the first length, and the first target region and the second target region are a long interspersed nuclear element (LINE);
• (b) quantifying a total mass of the isolated DNA in the composition;
• (c) quantifying a first concentration of the first target region and a second concentration of the second target region in the composition;
• (d) calculating a Q-ratio for the isolated DNA by dividing the second concentration by the first concentration;
• (e) determining a value for a quality-mass constant (kQm) by a method comprising:
• (i) sequencing a plurality of regions of a plurality of isolated DNA samples, wherein each of the isolated DNA samples has a known input mass and a known Q-ratio;
• (ii) comparing a fraction (FD) of the plurality of the regions with a selected depth of coverage as determined by sequencing in step (a) with a product of the input mass and the Q-ratio for each of the isolated DNA samples;
• (iii) identifying a minimum value for the product of the input mass and the Q-ratio at which FD is greater than a target FD;
• and (iv) setting the quality-mass constant (kQm) equal to the minimum value for the product of the input mass and the Q-ratio determined in step (iii);
• (f) estimating a required input mass for the isolated DNA by dividing the quality-mass constant (kQm) by the Q-ratio;
• and
• (g) preparing the isolated DNA for sequencing if the total mass of the isolated DNA in the composition is equal or greater than the required input mass.