The Helmholtz coils were housed in a purpose-built incubator situated in an electrically shielded room away from any MF sources and maintained at 37 °C by a flow of warm air from a distant source (2 m).
Culture tubes containing 5 ml of medium were placed within the pair of Helmholtz coils. Each coil was 180 mm in diameter and made of 100 turns of enamelled 0.7 mm diameter copper wire.
A sham exposure was conducted.
Control tubes were similarly cultured over a separate 72 h incubation period, but received no exposure to MFs. An independent person set the MF parameters that were unknown to the researcher.