3M recommends cleaning Littmann stethoscopes in-between every patient with a 70% isopropyl alcohol solution or wipe. Do not use hand sanitizer as a cleaning agent as there are additives that may damage parts of the stethoscope. Do not immerse your stethoscope in any liquid or subject it to any sterilization process. For more information on cleaning both electronic and mechanical stethoscopes, read the
Cleaning and Care page
in the My Stethoscope section.