Study type: Medical/biological study (experimental study)

Letter: Thermal denaturation of DNA exposed to 2450 MHz CW microwave radiation med./bio.

By: Hamrick PE
Published in: Radiat Res 1973; 56 (2): 400-404
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Aim of study (acc. to author)

To determine if there are any differential effects produced by heating with microwave radiation compared to heating in a water bath on denaturation of DNA.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: CW
Exposure duration: see additional information.

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Waveform
Exposure duration see additional information.
Modulation
Modulation type CW
Exposure setup
Exposure source
Setup 30 ml plastic tissue culture flask mounted on a styrofoam support which was surrounded by large panels (7 ft high) of microwave absorber.
Additional info Exposurte time: a) continous for 16 hr at 37°C in a sodium citrate buffer, b) 16 hrs at 37°C in a solution containing formaldhyde, c) 1 hr at > 37°C in a solution containing formaldehyde.
Parameters
Measurand Value Type Method Mass Remarks
power density 225 mW/cm² - calculated - at 50°C.
power density 940 W/m² - calculated - at 37°C.
power density 134 mW/cm² maximum measured - at 37°C.
power density 118 mW/cm² - calculated - at 40°C.
power density 158 mW/cm² - calculated - at 45°C.
Additional parameter details

Except for 134 mW/cm², all the other power densities stated below were absorbed power.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The experiments show that 2450 MHz (2.45 GHz) CW microwave irradiation under the exposure conditions employed has very little if any effect other than the effect of thermal heating on the secondary structure of DNA as determined by comparison of thermal denaturation curves.

Study character:

Study funded by