Optics

Fourfold-Changer

The Fourfold-Changer offers an alternative to the existing optical adjustable magnification options of the microscope manufacturers. An individual magnification of 4x, 2x und 1x can be selected by manually turning the dial. This enables to make magnification adjustments on a large scale without having to move the objective out of the chamber.
It is easily possible to change from the (1x) overview to the optically more detailed magnification (4x). This is equivalent to a magnification of 400 to 1600 with a 40x objective (using a 1-inch video-camera).
The changer is only for use with video-systems.

Technical Data

• Built-in 2x und 4x optics
• Adapter for various inserts
• includes C-Mount Adapter (1 inch!)
• easily adaptable for different microscopes.

Dodt Gradient Contrast (DGC)

This contrast system was developed in response to increasing demands in microscopy by Mr Dodt (MPI München). It enables to visualize the structures in sliced tissue.
Specific adjusting of the contrast enables various structures (horizontal or vertical) to be highlighted.
The Contrast is mounted between the microscope stand and the lamp housing. Since absolutely no contrast procedure is provided by the manufacturer, an independent and for all microscopes adaptable system has been developed.
In the same way it is also for the first time possible to obtain fluorescence and infra-red pictures simultaneously without any great effort.

Technical Data

• Contrast method as from Mr. H.-U. Dodt
• Developed for infra-red microscopy
• Available for all erect / inverse microscopy
• Adjustments can also be set motorized
• Independent to constitution and structure
• of the base of the chamber (thickness / material)

Factor-4 Photo-Tube

The Factor-4 Photo Tube allows the connection of three video cameras, which is particularly interesting for confocal set-up's. The Tube has a 100/100/100 division, meaning that it can be set on either 100% ocular, 100% upper port, 100% of the first rear port or 100% of the second rear port.
These possibilities enable the application of a scanning unit, an infra-red video camera, and additional detectors for the confocal system. Furthermore this allows the combination of the 2-Photon microscopy and that of the infra-optics whilst simultaneously being able to do electrophysiological recordings.
If requested, we can also build in dichroic prisms. These divide the spectrum at approximately 650nm and to nearly 100% into infra-red and ultra-violet.
This way pictures can be taken simultaneously from different camera ports.

Technical Data

• Binocular Photo-Tube for the BX Series
• Slider with 100/100/100 division
• Zeiss Cube with 100/100 division for the 2nd./3rd. Camera port.
• Application of dichroic prisms upon request.

Factor-3 Photo-Tube

The Factor-3 Photo-Tube allows the connection of one additional video camera.
We have installed a magnification-changer between the Tube and camera-mount, so that an individual magnification of 1x, 2x or 4x can be selected.
This Tube presents an ideal assistance to optical control when measuring fluorescence with simultaneous patch-clamping.
If requested, we can also build in dichroic prisms. These divide the spectrum at approximately 650nm and to nearly 100% into infra-red and ultra-violet.
This way pictures can be taken simultaneously from different camera ports.

Technical Data

• Binocular Photo-Tube for the BX Series
• Slider with 100/100/100 division
• Fourfold-changer for the 2nd. camera port
• (including 2x/ 4x optics)
• Application of dichroic prisms upon request.

Infrared-Guided Photostimulation

The infrared-guided photostimulation system allows one to stimulate neurons or parts of neurons in brain slices under visual control. The neurons are visualized by infrared video-microscopy in brain slices superfused with caged glutamate (0.2 - 1 mM) in Krebs-Ringer solution. The caged glutamate is per se inactive, but the cage can be opened by irradiation with UV-light. This results in the release of active glutamate which causes depolarisation of the neuron on which the UV-light spot is directed.

The infrared-guided photostimulation system can be used for two kinds of experiments:

1. Investigation of neurontransmitter sensitivity of the neuron recorded. For this kind of experiment, the neuron is isolated from synaptic input with TTX and the UV-light spot is directed on the soma or various parts of the apical dendrite. The response recorded indicates the sensitivity of the neuronal part onto which the caged neurotransmitter is released.

2. Investigation of neuronal circuits. Without the addition of TTX, many neurons can be scanned and stimulated and synaptic connections to the neuron recorded will be revealed by a synaptic potential following the UV-stimulation.

Photostimulation can be performed with either a Hg-arc lamp or a UV-laser.
The Hg-arc lamp is for many purposes powerful enough, giving sufficiently effective light spots in the 10µm range. The laser is needed to produce effective UV-spots in the 1µm range of short duration (3ms), thus mimicking synaptic stimulation. The unique feature of the infrared-guided photostimulation (developed by H.-U.Dodt) is its potential to stimulate selectively neurons identified visually by the completely non toxic infrared video microscopy.

Technical Data

• HBO 100W Housing
• 3 different neutral filter
• shutter + control
• fibreglass adjustment unit
• manipulator allows to adjust the spot in the centre of the field of view
• long fused silica fibre

Not Included

• epifluorescence condenser
• dichroic beamsplitter with cube