Scanning electron microscope image of Strongylocentrotus drobachiensus embryo at the primary mesenchyme blastula stage. Embryo was split open to reveal the outer epithelial layer and the blastocoel cavity at the vegetal pole. At this stage of embryonic development, primary mesenchyme cells are forming (flask shaped cells in the epithelial layer) and beginning to migrate into the blastocoel cavity. This image is part of a group of SEM images of sea urchin embryos at various stages of development. The group is available as CIL:39782-39791.
Biological Process: Embryonic morphogenesis, Cell migration
Images taken on a JEOL 35C SEM.
1. 2% GTA in 75% MBL SW or FilteredSW
FSW - fix for 1.5hrs. RT.
2. Rinse with 0.1M NaCacodylate buffer pH 7.4
3. 0.5% OSO4 in .075M NaCacodylate buffer pH 7.4 - 30' in the cold
4. Rinse in 0.1M NaCacodylate buffer ph 7.4
5. Dehydrate thru ETOH: 30%, 50%, 70%, 95% for 5 min each
6. 100% - 3 changes - 15' each
7. Critical Point Dry
8. Stick embryos down onto silver paint. Gently crack open with glass needle (pipette drawn out to a fine point).
9. Sputter coat with AuPd.
Author: Louisa Howard
Source: The Cell: An Image Library