Related Experiment Video
Updated: Aug 11, 2026

Preparation of Silica Nanoparticles Through Microwave-assisted Acid-catalysis
Published on: December 16, 2013
Mechanism of microwave sterilization in the dry state
D K Jeng1, K A Kaczmarek, A G Woodworth
1Advanced Sterilization Technology, Baxter Travenol Laboratories, Inc., Round Lake, Illinois 60073.
Abstract:
With an automated computerized temperature control and a specialized temperature measurement system, dry spores of Bacillus subtilis subsp. niger were treated with heat simultaneously in a convection dry-heat oven and a microwave oven. The temperature of the microwave oven was monitored such that the temperature profiles of the spore samples in both heat sources were nearly identical. Under these experimental conditions, we unequivocally demonstrated that the mechanism of sporicidal action of the microwaves was caused solely by thermal effects. Nonthermal effects were not significant in a dry microwave sterilization process. Both heating systems showed that a dwelling time of more than 45 min was required to sterilize 10(5) inoculated spores in dry glass vials at 137 degrees C. The D values of both heating systems were 88, 14, and 7 min at 117, 130, and 137 degrees C, respectively. The Z value was estimated to be 18 degrees C.
Related Concept Videos
Cleaning, Sterilization, and Disinfection
Cleaning
The cleaning process usually involves using water with detergents or enzymatic cleaner and removing foreign material from objects and surfaces, including organic material such as body fluids or inorganic material like soil. Cleaning is performed before high-level disinfection and sterilization because foreign materials on the cover of the devices interfere with process...
Methods of Sterilization I: Physical Methods
Steam sterilization uses non-toxic, low-cost moist heat in the form of saturated steam under pressure, which is fast, microbicidal, and sporicidal, and quickly warms and penetrates fabrics. Autoclaves, or steam sterilizers, expose each item to direct steam contact for a predetermined time at the necessary...
Methods of Sterilization II: Chemical Methods
Using chemical sterilization rather than heat to clean out equipment is recommended. It eradicates and removes all bacteria,...
Physical Methods for Controlling Microbial Growth: Temperature
Physical Methods for Controlling Microbial Growth: Radiation and Filtration
Key Techniques in Microbiology

