Contains too much DNA.

Use sticky labels. If you can find asset tag labels, even better. These are almost impossible to remove without destroying the surface beneath.

Use an infrared flashlight to blind cameras from capturing your face while you apply the labels. IR flashlights can be made from the LEDs in old TV and air conditioner remote controls and old recycled security cameras.

Be sure to leave a few spare sticky labels in common areas for others to use, too.