Knives and blood – how to clean them

Blood-borne pathogens are a bitch. Nobody wants to catch one of those. You have to know how to make sure you destroy any and all traces of blood-borne pathogens. The good news is, there are several ways.

So let’s say you use your knife to butcher a cow and cut yourself that succulent fillet you’ve been waiting all hunting season for. BUT WAIT! What if you beautiful steak-yielding trophy animal has mad cow disease (or something equally vicious). You can risk having intact DNA of such a virus on your blade. You need to wash it. Clean it. Sterilise it!

There are 3 general ways to destroy DNA (of viruses/bacteria/whatever):

1 – Heat

2 – Oxidation

3 – Denaturing



2 options. An autoclave or a flame. The problem with flames is that your knife isn’t uniform. There are all sorts of nook and crannies where blood and DNA containing cells (e.g. bacteria) can get where the heat just might not reach. Plus you may or may not want to reuse your knife.

Heat works by either causing anything flammable (e.g. carbon atoms in living matter) to combust, or by denaturing the proteins in the DNA/RNA of the pathogen.

And even if you don’t want to reuse you knife it’s just irresponsible to throw away a knife that might have the DNA of blood-borne pathogens on it, just waiting to contaminate the world. Take responsibility for your waste and sterilise before you throw shit away.



Yes, yes. Heat can cause oxidation. But outright combustion and oxidation will be treated differently here.

Oxidation usually requires either bleach or hydrogen peroxide. Whatever you choose make sure it isn’t the “thick” stuff. Get the cheap ass highly concentrated, very runny stuff. We don’t want to have anywhere the blood might have gone that is missed because the thickened bleach you got (for the nice fragrance) couldn’t get into that particular corner.

Take bloodied (at-risk-for-pathogens) knife, stick in container fill of bleach/peroxide. Lave for as long as you can. Rinse before bringing anywhere near clothing/the couch/the dog/your wife’s favourite shirt.



You can denature proteins (the stuff that makes up DNA) by making more bonds, or breaking down the bonds that already exist. Either way the proteins are connected in the same way in the same order, so the DNA/RNA containing pathogen can’t figure out which way the amino acids were originally bonded, so it cant do any harm.

You can denature a protein by high temperatures (covered already), or by the pH being too high or too low.

A high pH is caused by a caustic soda (sodium hydroxide) solution (possibly ammonia, but I’m not sure if the pH is quite high enough to work effectively). But because caustic soda is notorious for absorbing carbon dioxide from the air (making it not so caustic) it’s likely that any store brought sodium hydroxide might not be effective.

That leaves low pH and an acid. Pool acid, battery acid (I doubt vinegar will be low enough – but I’m not a medical person – i.e. I haven’t bothered to look up the pH of common vinegar and the pH at which most proteins begin denaturing).


Just so you know, the pool acid has the nasty ability to dissolve stainless steel, so your knife might not be the same again.


Same procedure – jut stick in a tub full of the acid and leave. Rinse before handling. Actually, the acid and peroxide can be nasty stuff, better to put the knife straight into a ziploc bag after cleaning it.



Don’t get a hunting knife with a wooden or material (e.g. paracord) handle. The DNA carrying pathogens can get into those things and nothing will get that DNA out (short of immense heat, and even then a cool spot can randomly form and mess everything up). If you don’t want blood-borne pathogens, stick with metal/solid plastic handles (preferably without minute dimpling/etching).

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