Microwave absorption by normal and tumor cells.

Energy levels exist in mammalian cells which result in the absorption of microwaves between 66 and 76 gigahertz. Many of these energy levels occur when water molecules associate with the various chemical groups of macromolecules. The absorption spectra of cells between 66 and 76 gigahertz, therefore, is determined by the structure of in vivo water lattices, and these seem to reflect indirectly the structural makeup of macromolecules or macromolecular complexes. Tumor cells absorb 66-, 68-, and 70-gigahertz microwaves less strongly and 69-, 72-, and 75-gigahertz microwaves more strongly than normal cells. These differences in the strength of attenuation at each frequency suggest that either the ratio of RNA to DNA or the relative number of certain types of chemical groups in tumor cells is different from that in normal cells.