Etchant in PBS was added to specified samples, followed by centrifugation and resuspension in media. Analysis was performed on a BD Accuri C6 Flow Cytometer. Ex vivo tissue penetration assay.

The vinegar and peroxide etchant is safe, cheap, and can be found in any grocery store on the planet. This experiment didn’t test other common etchants like HCl and H202, ...

The CuCl etchant sorta requires aeration, and that kicks stuff into the air as well; best done outside away from anything you don’t want corroded (but this is true of aeration of ANY etchant.) ...