Embryo collection - Acrylic resin
Kidneys were extracted from the embryo, fixed, treated and set in acrylic resin.
The mother was anaesthetised then perfusion fixed with fresh 4% paraformaldehyde in PBS at 4oC. The embryos were removed and placed in fresh fix overnight at 4% on a roller. Kidneys were dissected out with adrenal glands still attached. Perfusion fixation is probably not required for embryonic kidneys so they can be dissected fresh from the embryos and immersion fixed.
Dehydration and infiltration
Once fixation was completed, the kidneys were dehydrated in a series of ethanol concentrations up to 70% ethanol (1hr per change) and stored at 4oC. Prior to embedding the tissues were further dehydrated in a series up to 100% ethanol ( 3x1hr minimum) then placed in LR White acrylic resin overnight at 4oC.Next day the LRWhite resin was replaced with fresh resin and the kidneys left overnight at 4oC.
A kidney was embedded in the resin plus accelerator in a flat-bottomed foil dish allowed settle. The resin block was kept on ice overnight until it had completely polymerised. The next day the kidney was cut out with a small saw and the block trimmed of excess resin with a single-edged razor blade. The block was then photographed.
The embryos were then subject to histology sectioning