A simple osmium post-fixation paraffin-embedment technique to identify lipid accumulation in fish liver using medaka (Oryzias latipes) eggs and eleutheroembryos as lipid rich models

J. A. Mondon, J. Howitt, M. Tosiano, Wing Hin Kevin Patrick Kwok, D. E. Hinton

Research output: Journal article publicationJournal articleAcademic researchpeer-review

2 Citations (Scopus)


Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.
Original languageEnglish
Pages (from-to)86-90
Number of pages5
JournalMarine Pollution Bulletin
Issue number5-12
Publication statusPublished - 17 May 2011
Externally publishedYes


  • Lipidosis
  • Liver
  • Medaka
  • Osmium post-fixation
  • Paraffin

ASJC Scopus subject areas

  • Aquatic Science
  • Oceanography
  • Pollution

Cite this