Anything Q posts is up to subjective interpretation. Since the content is cryptic and Q utilizes words and symbols with multiple meanings, you will always have multiple interpretations. None may be correct. One, or several may be correct. The author isn't clarifying.

1. DNA is identity. It's your biological identity that's half your mom and half your dad plus whatever mutations you picked up when the DNA was copied and chromosomes crossed over. We think about this in terms of trans people and their desire to change their identity, but who are not able to because their DNA precludes that.

2. There are things that can change your DNA. Biochemists recognize that the molecule is ultimately rather fragile. Anyone who's ever studied paleontology knows that natural forces rapidly break it down so we lose the genetic identity of dead creatures unless we get really lucky and find some preserved, protected in things like hard bone or teeth, or preserved by extraordinary circumstance like rapid burial in ice (like the ice man and the ice mammoth specimens). Many chemicals cause DNA change (carcinogens, mutagens, teratogens, etc). Sunlight and similar EM radiation causes it, etc. Your body's cells have robust DNA repair mechanisms that counteract these forces at normal levels of exposure. Some species are more resilient than we are.

3. When DNA does mutate and the DNA can't be repaired, sometimes it's meaningless. But, hit the right cellular pathways that control growth: your stop signals and your grow signals, we call that cancer.

4. DNA sequences can be patented. Nearly every DNA sequence on the planet is patented by the researchers who sequenced it. It took money to make that information product, so the law protects it as intellectual property, and "creative" biomedical companies' lawyers have tried to lay claim to all sorts of things, including their customers' genetic sequences. Given that DNA is your identity, AND we can fully sequence a human being (all ~3 billion bp) in an afternoon for under $1,000, and we can get a "fingerprint" of key markers a lot faster than that, there is discussion about using DNA as a unique biometric ID to support any number of security concerns, most notably a police state.

5. Ascension hints at transhumanism. Anyone who's ever seen Gattaca knows this debate. We can customize DNA. Currently, we have only a crude understanding of how that DNA leads to us. That's a good thing, because there are people who want to make designer humans. Who want to "play God" in the sense of creating their own life in their own desired image. It's an inherently risky thing to do, but people do wish to change themselves from what they are into something else that they wish they could be. DNA is seen as the pathway to do that.

So, when Q says "protect your DNA", he could be referring to your biological identity, you biological blueprint that makes you who you are, to protecting your health from cancer, or to protecting your biometrics from the encroaching surveillance state, or simply to embrace who you are as God/Nature made you. Those are my multiple interpretations.

As with all things Q, do your own thinking, and support it with your own research, evidence, and logical reasoning.