High resolution raster-scan optoacoustic mesoscopy of genetically modified <em>Drosophila pupae</em>.

We developed an optoacoustic mesoscopy system based on a high frequency transducer, with a bandwidth of 25-125 MHz. The system is to penetrate more than 5 mm, at a resolution of 7 &micro;m axially and 30&micro;m transversally. After characterizing the system we used it to image a genetically modified drosophila fly and pupae, both expressing GFP from the wings. We were able to generate high resolution, 3-dimensional images in both cases, a stronger signal could be observed from the wings in the fly, and from the location corresponding to the future wings in the pupae