10
Appendix C
How to Disinfect Lumascope Microscopes
Etaluma’s microscopes are revolutionary in their ability to be operated within cell culture incubators,
providing the most stable and robust long term live cell imaging. Placing the LS Microscope in the incubator
often includes a disinfection step before installing. In this Tech Note, we discuss the methods
recommended.
Wiping Down with Alcohol
Ethyl and isopropyl alcohols are the two most widely used alcohols because of their biocidal activity.
Alcohols work through the disruption of cellular membranes, solubilization of lipids, and denaturation of
proteins. These processes
require water so the alcohols must be diluted to 60-90% in water to be effective.
These alcohols are effective against lipid-containing viruses and a broad spectrum of bacterial species, but
are ineffective against spore-forming bacteria. They also evaporate rapidly, which makes extended contact
times difficult to achieve unless the items are immersed.
As mentioned above, the optimum bactericidal concentration for ethanol and isopropanol is in the range of
60% to 90% (typically 70%) by volume. Alcohols are generally regarded as being non-corrosive.
Wiping Down with Bleach
Chlorine compounds are good disinfectants, have a broad spectrum of antimicrobial activity, and are
inexpensive and fast acting. Hypochlorites, the most widely used of the chlorine disinfectants, are available
in liquid (e.g., sodium hypochlorite such as in household bleach) and solid (e.g., calcium hypochlorite,
sodium dichloroisocyanurate) forms. Household bleach has an available chlorine content of 5.25%, or
52,500 ppm. Because of its oxidizing power, it loses potency quickly and
should be made fresh
and used
within the same day it is prepared.
Exposure to Hydrogen Peroxide Vapor (HPV)
Hydrogen Peroxide Vapor (HPV) is another chemical that is effective in removing biological agents from the
surfaces of equipment and other difficult-to-sterilize surfaces. The ability of vapor to reach a wide variety of
desired areas means it is effective in sterilizing pass-through chambers and devices used in hospitals and
manufacturing settings.
HPV’s ability to decontaminate
incubators without the use of heat offers significant
advantages in research laboratories in which costly down time must be avoided. The combination of a
seven-minute HPV fog in the chamber with circulation by the incubator airflow blower, followed by
exposure to narrow-bandwidth ultraviolet light, provides an effective antimicrobial disinfection. Further, it
reaches all incubator walls, shelves, reservoirs, air plenums, sensors, and other interior components, and it
leaves only small amounts of sterile water droplets as a residual.
For questions, contact Technical Support at
