Fig. 1.

CARS and DIC images in living oocytes, eggs and early embryonic stages. (A-G) DIC images (single z-plane, except E, which is a maximum intensity projection) representative of populations of mouse eggs and embryos, from (A) immature GV stage (n=∼90), (B) MII eggs (n=∼70), (C) two-cell (n=∼65), (D) four-cell (n=∼60), (E) eight-cell (n=∼10), (F) morula (n=∼35) and (G) blastocyst stage (n=∼20) embryos using a 1.27 NA water objective and a 1.4 NA oil condenser. (H-N) Depth colour-coded images of CARS z-stacks at wavenumber 2850 cm⁻¹ through the same eggs and embryos, showing LDs throughout these developmental stages. Inset in (I) shows a typical LD cluster seen at this stage. 0.1×0.1 µm xy pixel size; 0.5 µm z-step; 0.01 ms pixel dwell time; ∼14 mW (∼9 mW) pump (Stokes) power at the sample. Scale bars: 10 µm. Colour bar shows depth colour-coding from –25 µm-25 µm of 101 z-stacks (0 µm being the approximately equatorial plane of the egg or embryo), the brightness of each colour is the maximum intensity at each corresponding z-plane. Data from ≥2 trials, using 1-3 mice each.