In situ preparation of colloidal iron by microwave irradiation for transmission electron microscopy.
We attempted to prepare colloidal iron within tissues by means of microwave irradiation. Mouse tissue blocks were fixed with a mixture of paraformaldehyde and ferric chloride in a cacodylate buffer, immersed in a cacodylate buffered ferric chloride solution, and irradiated in a microwave processor. Colloidal iron was prepared within tissues or cells, and was observed in the form of electron dense fine granules (1-2 nm in diameter) by transmission electron microscopy. Collagen fibrils in the connective tissue showed colloidal iron deposition at regular periodical intervals. Cells in the splenic tissue showed that fine colloidal granules were deposited on the ribosomes but not on the nuclear chromatin. This finding suggests that ferric ions could not diffuse into the nucleus, which was surrounded by the nuclear envelope. The podocyte processes of the renal glomerulus were stained diffusedly. Though this microwave in situ colloidal iron preparation method has some limitations, it is convenient for use in biomedical specimen preparation in transmission electron microscopy.
Nakatani
Satoru
S
Department of Human Morphology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
Naito
Ichiro
I
Momota
Ryusuke
R
Hinenoya
Noriko
N
Horiuchi
Kanji
K
Nishida
Keiichiro
K
Ohtsuka
Aiji
A
D000818:Animals; D003102:Colloids / Q000737:chemistry*; D005260:Female; D007501:Iron / Q000737:chemistry*; D007668:Kidney / Q000737:chemistry / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D008872:Microwaves; D013154:Spleen / Q000737:chemistry / Q000648:ultrastructure; D013194:Staining and Labeling / Q000379:methods*
D003102:Colloids; D007501:Iron