Cool tools:
Making the invisible visible
Blood flow in the brain changes as we age, a fact which may affect our risk of having a stroke.
Dr. Jonathan Lytton with the Axioskop
With a rack of electronics that looks as if it belongs at a rock concert, the fixed-stage Zeiss Axioskop 2 FS Plus is the gold standard for microscopes in the physiology lab. This small miracle of modern technology is used in the life sciences to examine minute parts of living specimens, such as wafer-thin layers of live nerve-cell tissue. Such live investigations are possible thanks to a temperature-controlled chamber and optical objectives (the "eyepieces" of the microscope that house the lenses) that can be immersed in a saltwater solution.
Once under the microscope's lenses, specimens can be illuminated by different methods to provide the best possible viewing. For example, the Axioskop allows scientists to use fluorescent dyes to help them observe cellular activity. When fluorescence is used, the Axioskop must be housed in a room that can be completely darkened-something akin to a photographer's darkroom. A super-sensitive camera detects the fluorescence and sends images to a computer monitor. The Axioskop can also illuminate specimens using light in the infrared range.
Researchers may customize their Axioskops with many accessories. Micromanipulators-small, delicate "arms"-can hold electrodes to measure the electrical activity in cells or wield instruments to carry out tasks too complex for the naked eye. A motorized stage, operated by means of a joystick, facilitates seamless and vibration-free examination of an entire specimen. A special copper screen surrounds the Axioskop to block electrical interference. The Axioskop may even come equipped with a laser capable of breaking open chemical bonds, useful for isolating certain chemicals under investigation.
The most important add-on to a Zeiss Axioskop, however, is the highly skilled technician required to make it work. Graduate students or post-doctoral electrophysiologists are in high demand as operators of this type of equipment.