imageColin Berry asks:

All of a sudden, the penny dropped. Never mind the potassium for now. WHAT ABOUT THE SODIUM?  Blood is salty. It’s loaded with sodium chloride, NaCl, or Na+Cl-. Why have I never seen mentions of sodium in connection with the Shroud and those “blood stains”? Now here’s something curious. Enter…  shroud turin blood sodium… into your favourite search engine, and look at the returns. You will find at best a few passing mentions of sodium, but nothing to suggest that it has been systematically investigated as a stable marker for old blood or serum stains. How weird is that?

[ . . . ]

Legitimate question? Okay! Needs to be answered. But then, this. Is he thinking conspiracy theory?

So what’s going on here, or rather NOT been going on? Why has the absence  – or at any rate near-absence of sodium – not been reported and commented upon by that group presently assembled in Valencia as we speak, the ones  who were given privileged access to the Shroud for a week in 1978, the ones who effectively now operate as an old boy network?

Source: What about sodium as Na+, that seemingly forgotten marker for blood