Ultra-high frequency acoustic impedance maps of MCF-7 cells

Acoustic impedance maps can be used to gain an insight into the microstructure and physiological state of cancer cells. In this we correlated acoustic impedance maps with cells structures detected by fluorescence microscopy. Fluorescence microscope was used to image MCF-7 cells marked with Celltracker Orange and Hoechst for staining the cytoplasm and nucleus, respectively. A single element 375MHz center frequency transducer (SASAM) was used to generate acoustic impedance maps of inverted MCF-7 cells on a plastic substrate. The acoustic impedance of 20 single-live, 10 clustered-live and 7 clustered-fixed MCF7 cells were measured and compared. Fluorescent images and acoustic impedance maps suggest that there is an acoustic impedance mismatch between the nucleus and the cytoplasm. The average acoustic impedance values for single-live, clustered-live and clustered-fixed cancer cells were measured to be 1.600±0.006 MRayl, 1.609±0.009 MRayl and 1.572±0.011 MRayl.