Zamboni’s embryo fixative solution is a fixative often used to enhance nuclear fixation. It is a popular fixative for embryonic studies, due to its excellent preservation of nuclei and chromosomes.Our modified Zamboni’s solution is a ready-to-use fixative especially suitable for the fixation of embryonic tissues. This solution is freshly made from paraformaldehyde powder and picric acid and packaged in polyethylene or glass vials of convenient tissue-sample size (20 ml) with leak-proof caps. It may be stored at room temperature for 12 months without change of the original quality.