Yup.
“To build a bioweapon, living cells would be the true target (although dead cells may suffice as soon as a decade from now). These are more difficult to recover. A strand of hair, for example, is dead, but if that hair contains a follicle, it also contains living cells. A sample gathered from fresh blood or saliva, or even a sneeze, caught in a discarded tissue, could suffice. Once recovered, these living cells can be cultured, providing a continuous supply of research material.
Even if Secret Service agents were able to sweep up all the shed cells from the president’s current environs, they couldn’t stop the recovery of DNA from the president’s past.”
Sauce: https://www.theatlantic.com/magazine/archive/2012/11/hacking-the-presidents-dna/309147/