Interleaving optical coherence microscopy with dual-channel fluorescence microscopy for simultaneous co-registration of structural and functional information

Multimodal imaging systems offer the opportunity to scrutinize different properties of biological samples. Optical coherence microscopy (OCM) is a non-invasive and high-resolution imaging technique capable of generating three-dimensional images of tissue. In this work, a multimodal imaging system interleaving OCM with a dual-channel fluorescence microscopy (DC-FM) system was developed to add functional imaging capabilities to OCM. The combined system was able to simultaneously acquire both reflectance and fluorescence data from the same location of the sample at the speed of 250 kHz, and with a lateral resolution of similar to 2.1 mu m. An axial resolution of 2.4 mu m in sample over the imaging depth of 1 mm was achieved with OCM. The performances of the combined system were evaluated by imaging a multi-layer tape as well as a gel containing green and red fluorescent microspheres. While OCM enabled the depth localization of all fluorescent microspheres, it was not able to discriminate between green and red fluorophores, a feature that was achieved with DC-FM. Hence, the interleaved system has the potential of assessing structural as well as cellular level functional changes in biological samples. This system will be applied toward longitudinal studies in small animal models.