A simple method of alpha irradiation for experiments in radiobiology

This paper presents an irradiation system for radiobiology experiments using alpha particles in vitro. Irradiation is delivered to the cells by the presence of radioactive isotopes previously dissolved in the culture medium. The system uses a source of 226Ra from which the radon (222Rn) generated diffuses through the apparatus and is dissolved in a standard culture medium subsequently used for cell culture. The radioactive elements present are the naturally occurring radioactive gas radon and its short-life progeny. The radiation delivered to the cells is mainly composed of alpha particles from 222Rn and its daughters 218Po and 214Po. The doses absorbed by the cell cultures range from 1 to 1000 mGy depending on the conditions of exposure. To illustrate use of the system, we present results obtained when low doses of alpha particles were employed to irradiate CD34+ hematopoietic progenitor cells and MCF-7 human breast cancer cells