Question

By types, I mean several different species of animals. If, post extraction, the pure, isolated DNA of several different animals were mixed together and run through DNA analysis, I know the results would be inconclusive, but would there be any usable information returned at all? Would any species be individually identifiable?

The scenario is hypothetical and for a TTRPG plot; the players procured samples of a substance that they don't yet know are isolated DNA polymers (think the extracting strawberry DNA science experiment for children) from several different species of animals and a couple of humans, which was mixed together post-extraction. They'd like to have the DNA samples analyzed. Handwaving turnaround time (I know this process would realistically take weeks to months at the bare minimum, but if crime procedurals can deus-ex analysis results in 48 hours, so can my players), what would that analysis turn up?
Would they be able to parse specific species, or the ratio of one species to another (ie the sample only containing one or two dogs, but many, many small birds and squirrels)? They almost certainly wouldn't be able to turn up any kind of identifiable information on the human DNA, even with an uncontaminated reference sample, right?

Answer 1

With modern DNA analysis technologies, the mixed isolated DNA of several animals and humans could provide usable information. Species can be identified through genetic barcodes and techniques like PCR and qPCR, which also help estimate the ratio of one species to another. Human identification is also possible with reference samples.

Step-by-step explanation:

If the isolated DNA of different animals is mixed together and analyzed, the results would indeed be complex, but not completely inconclusive. With advanced DNA sequencing and analysis techniques such as polymerase chain reaction (PCR) and next-generation sequencing, it's possible to sort through the complex mixture of DNA. These techniques can amplify and sequence the DNA, allowing scientists to compare the sequences against known genomic databases.

Specific species can potentially be identified through their unique genetic markers, known as barcodes, which differ between species. The relative abundance or ratio of DNA from each species may also be estimated using quantitative PCR (qPCR) techniques. These strategies enable the determination of whether there are DNA sequences indicating one species is present in greater quantities than another.

As for human DNA, forensic analysis could potentially identify individuals if reference samples are available for comparison. STR loci and mitochondrial DNA sequencing are forensic tools that could be used for this purpose. However, without reference samples, the human DNA would not reveal personal identities but could still confirm human DNA presence among the mix.