A comparison of the atomic composition of siderosomes (haemosiderin) in cryosections of unfixed frozen tissues and Epon-embedded tissues.
Siderosomes (i.e. single membrane-bound lysosomal bodies containing haemosiderin) were produced in the liver and muscle of rats by injections of iron dextran. Electron-probe X-ray analysis was executed on siderosomes in cryosections of quick-frozen fresh unfixed tissues (liver and muscle) and sections of Epon-embedded tissues. There were no statistically significant differences between the ratios of iron:phosphorus and iron:sulphur in these two types of preparations. Hence it is concluded that there is no significant loss or gain of phosphorus or sulphur during preparation of tissues for Epon embedding. The results confirm past belief that so little phosphorus or sulphur is present in siderosomes that haemosiderin is best regarded as ferric hydroxide oxide. A new finding in the present study was the demonstration of small amounts of potassium in siderosomes in cryosections. It seems that potassium is lost (leaches out) from siderosomes during preparation of tissues for Epon-embedding.
Ghadially
F N
FN
Department of Pathology, Ottawa Civic Hospital, Canada.
Lalonde
J M
JM
D000818:Animals; D015925:Cryopreservation; D016616:Cryoultramicrotomy; D004577:Electron Probe Microanalysis; D006485:Hemosiderin / Q000032:analysis*; D007501:Iron / Q000032:analysis; D007668:Kidney / Q000737:chemistry* / Q000648:ultrastructure; D008099:Liver / Q000737:chemistry* / Q000648:ultrastructure; D008247:Lysosomes / Q000737:chemistry* / Q000648:ultrastructure; D008854:Microscopy, Electron; D010758:Phosphorus / Q000032:analysis; D011188:Potassium / Q000032:analysis; D051381:Rats; D013455:Sulfur / Q000032:analysis
D010758:Phosphorus; D013455:Sulfur; D006485:Hemosiderin; D007501:Iron; D011188:Potassium