title: Peroxisome determination in optical microscopy: a useful tool derived by a simplification of an old ultrastructural technique.
abstract: Peroxisomes are able to respond to changes in the cellular environment by adapting their number, morphology and metabolic functions. Recently interest in peroxisomes and their possible roles in physiological and pathological processes have significantly increased. In order to identify peroxisomes, several cytochemical techniques have been developed that require fairly complex procedures or are too expensive to be used for screening. In this paper we show that it is possible to label peroxisomes in several cell lines and in tissues by a simple and cheap technique based on 3,3'-diaminobenzidine (DAB) reactivity. The number of peroxisomes detected with this technique in each cell line was similar to that shown by catalase immunoreaction. The technique appears specific because it was able to detect increased number of peroxisomes after treatment with the specific PPARγ antagonist G3335. Gomori's technique for acid phosphatase activity was used to demonstrate that the DAB positive organelles were not lysosomes. The DAB technique has also been applied to transmission electron microscopy, where it labels round structures that are identified as peroxisomes on the basis of morphology, size and localization. The DAB technique has proved to be specific, simple, fast and cheap, which make it ideal to screen possible peroxisome changes in physiological and pathological conditions.
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Viale G. Pieraccini 6, Florence, Italy. Electronic address: lorenzo.cinci@unifi.it.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Cinci
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Viale G. Pieraccini 6, Florence, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Di Cesare Mannelli
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Viale G. Pieraccini 6, Florence, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Zanardelli
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Viale G. Pieraccini 6, Florence, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Micheli
authors.affiliation: Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Viale Pieraccini 6, Florence, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Guasti
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Viale G. Pieraccini 6, Florence, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Ghelardini
mesh_terms: D015100:3,3'-Diaminobenzidine / Q000737:chemistry; D000818:Animals; D001253:Astrocytes / Q000648:ultrastructure; D002460:Cell Line; D007668:Kidney / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D020675:Peroxisomes / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D015100:3,3'-Diaminobenzidine
keywords: Astrocytes; Electron microscopy; Fibroblasts; Human hepato-cellular carcinoma; Immunocytochemistry; Macrophages; Peroxisomes