Zebrafish embryo at 110 hours post-fertilization with reporter-gene-driven fluorescence in the thyroid gland. Ventral views; anterior is on the left. Fluorescence images using the adaptive microscope without (a) and with (b) spherical aberration correction. The images are normalized separately to show the intensities using the full colour range. (c) The measured region is approximately marked in the standard wide-field image of the whole embryo. (d) The line profiles of the grey values of the non-normalized fluorescence images are taken at specific rows, where the positions of the lineouts are indicated by the green and black numbers in (a,b,d). The lineouts of the fluorescence images indicate that aberration correction leads to increased signal intensity and better optical sectioning. The dimensions are (100 × 308) m² (a,b), approximately (1.5 × 5) mm² (c) and (70 × 308) m² (d).