Optical coherence tomography of developing embryonic morphology

Summary form only given. Recent advances in molecular biology techniques have permitted the site specific insertion of predetermined mutations into embryos for the investigation of normal and abnormal development. Currently, there are several imaging modalities available to observe the expression of genetic mutations, but these typically require small, transparent, or fixed specimens. Optical coherence tomography (OCT) offers the ability to image in vivo developing morphology in many of the animal models used for genetic studies. In addition, OCT has the potential to rapidly and repeatedly acquire optical histology to assess development and to identify the expression of normal and abnormal genes. Optical coherence tomography is an imaging modality that permits the in vivo investigation of biological specimens on the micron scale. The imaging technique can be thought of as an analog to ultrasound B-mode imaging except backscattering of light from biological tissue layers is detected rather than acoustic reflections. OCT incorporates a fiber-optic-based Michelson interferometer using a 1300-nm low-coherent superluminescent diode (SLD) as its light source to measure the intensity of optical backscattering from within the specimen. OCT images are shown of in vivo developing morphology from a leopard frog tadpole.