Imaging Parhyale hawaiensis embryogenesis with frequency domain photoacoustic microscopy: A novel tool in developmental biology.

We present the application of a low-cost frequency domain photoacoustic (FDPA) microscope for the label-free imaging of live developing embryos of the crustacean model organism Parhyale hawaiensis. By modulating the intensity of a continuous wave laser source at 9.5 MHz, we achieve the excitation of monochromatic PA waves, which are detected to provide amplitude and phase recordings. The data are subsequently processed to generate accurate maximum amplitude projection and surface reconstructions, delineating the morphological features of the embryos with high resolution and contrast. The findings of this study pave the way for the broader adoption of inexpensive PA diagnostic techniques in developmental biology, shedding light on various fundamental processes in established and emerging model organisms.