The inventive concepts presented herein relate to methods of identifying molecules identification of molecules using apparatuses including: electromagnetic write-head(s); magneto-resistive read sensor(s), and processor(s). An exemplary method includes scanning one or more of a plurality of biosample tracks of a biosample substrate using an electromagnetic write-head to magnetically excite one or more molecules of interest using an alternating magnetic field. The one or more molecules of interest are disposed on one or more of the biosample tracks. A resonant response of the one or more molecules of interest is measured using a magneto-resistive sensor. The resonant response is compared to a table of known resonant responses to identify the one or more molecules of interest.