Zeiss Axiovert 200 - 3.3.4 Setting of VAREL contrast in transmitted light

OPERATION
Carl Zeiss Illumination and contrasting techniques Axiovert 200
3-38 B 40-080 e 03/01
3.3.4 Setting of VAREL contrast in transmitted light
3.3.4.1 General principle
VAREL contrast provides a relief-like image of objects and can be used as an alternative to phase
contrast. VAREL contrast can also be used on curved surfaces, e.g. 96-well microtiter plates, for which
no contrast can be achieved with the phase contrast technique (no flush ring positioning!).
3.3.4.2 Configuration of the Axiovert 200 (manual) and Axiovert 200 M
− Condenser with turret equipped with VAREL stops.
− Objectives which are suitable for VAREL contrast, e.g. A-Plan Ph1Var1 or LD A-Plan Ph2Var2.
3.3.4.3 Setting of VAREL on the Axiovert
200 (manual) and Axiovert 200 M
• Open the aperture diaphragm (3-21/1)
completely.
• Swing VAREL stop on the turret of the
condenser into the beam path (Var position).
• Swing in the required VAREL objective via the
nosepiece.
• Use the setting screw (3-21/2) to move the
Varel diaphragm opening until optimum VAREL
contrast is achieved (relief-like impression).
☞
Microtiter plates:
Select the opposite VAREL ring of the diaphragm for illumination at the edge of the cavity; in
the center of the cavity, the right or left VAREL ring can be used.
Fig. 3-21 Setting of VAREL contrast