A new gene detection technique that is fast, inexpensive, and easy-to-use is urgently needed in hospitals, clinics, and laboratories without access to expensive equipments. The lack of a practical, minimally invasive, and economical method constitutes the main impediment to the promotion of genetic medicine in developing countries. Radiofrequency scattering parameters are an inexpensive gene sensor potentially capable of noninvasively identifying biological materials. They represent a quantitative value for the electromagnetic reflection/transmission characteristics of certain molecular markers in a given frequency domain. The S21 parameter is the difference between the signal received and that transmitted. The aim of this study is to evaluate the S21 transmittance parameters (magnitude and phase) as an indirect impedance measurement for detecting the label-free complementary deoxyribonucleic acid (cDNA) amplification of the 16S ribosomal subunit gene. S21 values showed differences associated with distinct cDNA concentrations. Hence, this technique could possibly facilitate the design of an inexpensive, label-free, and easy-to-use gene sensor.