Brief communication: Improved fixation and contrast of insect malpighian tubules using osmium tetroxide-potassium ferricyanide
✍ Scribed by Felgenhauer, Bruce E.; Spring, Jeffrey H.; Bordelon, Charmaine M.
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 777 KB
- Volume
- 35
- Category
- Article
- ISSN
- 1059-910X
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✦ Synopsis
Introduction-
The Malpighlan tubules of insects were first described more than four centuries ago and have been recognized as the primary organs of excretion for nearly two. In the last fifty years they have been the subject of considerable interest because of their prodigious capacity for fluid transport (reviewed by Bradley, 1985; Spring, 1990;. The blood-sucking bug, Rhodnius, for example, can increase fluid transport by the tubules more than lOOOX in response to endocrine stimulation (Maddrell, 198 1). Because of their transport abilities, there have been many studies of the ultrastructure of these organs (reviewed by Bradley, 1985). Malpighlan tubules of insects have historically been difficult to preserve satisfactorily for transmission electron microscopy (reviewed by Bradley, 1985). In the course of our investigations of the intracellular events and ultrastructural changes of Acheta Malpighian tubules following endocrine stimulation, we encountered significant preservation problems using standard glutaraldehyde and osmium tetroxide fixation . In this note we describe the application of secondary fixation by osmium tetroxide-potassium ferricyanide, a method commonly used in different plant tissue protocols (e.g., Cresti and Keijzer, 1985; Hepler, 1980; Schnept et al., 1982). The method described here provided superb fixation and excellent contrast compared to conventional methods of specimen preparation of insect Malpighian tubules.