Polarization second harmonic generation microscopy provides quantitative enhanced molecular specificity for tissue diagnostics

摘要

Due to specific structural organization at the molecular level, several biomolecules (e.g., collagen, myosin etc.) which are strong generators of second harmonic generation (SHG) signals, exhibit unique responses depending on the polarization of the excitation light. By using the polarization second harmonic generation (p-SHG) technique, the values of the second order susceptibility components can be used to differentiate the types of molecule, which cannot be done by the use of a standard SHG intensity image. In this report we discuss how to implement p-SHG on a commercial multiphoton microscope and overcome potential artifacts in susceptibility () image. Furthermore we explore the potential of p-SHG microscopy by applying the technique to different types of tissue in order to determine corresponding reference values of the ratio of second-order tensor elements. These values may be used as a bio-marker to detect any structural alterations in pathological tissue for diagnostic purposes.