Genetic anonymity (AdBlock my genome)

Every contact leaves a trace, and in this day and age (actually for years now), traces mean cheap, precise genetic identification. In other words, once known, any individual can be identified as having been present at almost any location.

This is done by cheaply and selectively reading your DNA at hundreds of thousands of locations and comparing these variables to those in an environmental sample, like a sophisticated molecular fingerprint.

What does this mean for spies?

Don't you think your government would love a genetic database of all known operatives? How can they protect their spies from becoming known? (Assuming double agents haven't already been quietly swabbing the door handles?)

Actually, I'm suddenly wondering what happens to those swabs they check your bags with at the airport... Thinking about it, it's almost cheep enough to monitor a database of all known individuals in near real time! Facial recognition? Pah!

So what should a spy do?

Genetic anonymity is easier than you think! Lets imagine they really are genotyping environmental samples (in airports). The standard protocol for almost any such test involves a genome amplification step (like this one), where the DNA in the sample is amplified.

Any amplification process is prone to feedback. Using so called 'poison primers' (primer dimers), for example, any PCR amplification step can be ruined (subverted).

This is why spies (and smarter criminals) actually wear poison primers on their clothes. A tiny, tiny contamination of such poison primers can ruin the PCR amplification protocol by selectively amplifying themselves over the intended sample. Each round of amplification creates more poison primers, irrevocably 'poisoning' the reaction.

The result? Genetic identification tests based on PCR fail wherever you go. You're a massive blind spot on the surveillance network. Interestingly, anyone specifically testing for such primers would spot you a mile off... like tattooing a third eye on your forehead to evade facial recognition; OK, you're algorithmically invisible, but you stand out like a freak.

But can it be so easy? No it can't, why did you ask?

Isothermal whole genome amplification is a common method that seeks to amplify genomic DNA without some of the pitfalls of PCR (such as poison primers). However, (we're speculating here right?) each increasingly sophisticated genotyping method can be subverted with an increasingly complex molecular 'countermeasure', effectively 'jamming' the protocol.

Thus we can imagine an arms race, with genotyping protocols developing specific anti-jamming measures to get round the latest molecular jamming techniques. Ultimately, this kind of molecular biology is akin to computer programming.

And where there's programmers, there's hackers.

Let's suppose that spy A, visits a crime scene, leaves a trace of her molecular program ... a program so sophisticated that it hacks the very protocol designed to negate its effect, specifically altering the test result to falsely implicate spy B in the crime committed.