Related Experiment Video
Updated: Jun 19, 2026

Intestinal Epithelial Regeneration in Response to Ionizing Irradiation
Published on: July 27, 2022
Inactivation of Giardia lamblia cysts by cobalt-60 irradiation
Christine A Sundermann1, Barbara H Estridge
1Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA. sundeca@auburn.edu
Abstract:
Cysts of Giardia lamblia can be a contaminant of water and food that can infect humans and cause the zoonotic disease giardiasis. Irradiation by a cobalt-60 source was investigated for its ability to inactivate cysts such that they would not be infective to gerbils. Cysts that received doses of radiation ranging from 0.25 to 2.0 kGy, with a recovery period of 6 hr or less, did not infect gerbils. Cysts that were irradiated at 0.25 kGy and allowed to recover at 23 C in water for 24 hr or longer were infective. Temperature had an effect on the ability of cysts to regain infectivity in that cysts allowed to recover at 4 C after irradiation were not infective. Therefore, recovery time and temperature are important parameters for determination of the doses that are necessary for inactivation of this pathogen. The ability of staining with propidium iodide to predict infectivity of cysts was tested. Cysts that were damaged by higher doses of radiation and were not infective to gerbils stained similarly to viable cysts that were infective. Thus, propidium iodide is not a reliable indicator of viability and infectivity of cysts that have been treated with gamma radiation.
More Related Videos
11:40A Co-culture Method to Investigate the Crosstalk Between X-ray Irradiated Caco-2 Cells and PBMC
Published on: January 30, 2018
12:11A Modified EPA Method 1623 that Uses Tangential Flow Hollow-fiber Ultrafiltration and Heat Dissociation Steps to Detect Waterborne Cryptosporidium and Giardia spp.
Published on: July 9, 2012
Related Concept Videos
Giardiasis
Antiprotozoal Agents
Physical Methods for Controlling Microbial Growth: Radiation and Filtration
Microbial Bioremediation of Uranium