Levenhuk MED PRO 600 Fluo Guia Del Usuario página 16

• check the microscope illumination setup (the condenser aperture diaphragm shall be open by size of the lens eye or by 2/3
of the eye size).
Observation of objects in fluorescence light
Mercury-filled lamp activation and illumination setup
Connect the mercury-filled lamp power supply unit to the grid. Activate the mercury-filled lamp by putting the power switch in "I"
position.
It takes at least 10 minutes for the mercury-filled lamp to reach operating parameters. Normal mode of lamp operation means that
amperemeter and voltmeter arrows are in the middle of the scale.
WARNING! DO NOT DEACTIVATE THE MERCURY-FILLED LAMP EARLIER THAN 15 MINUTES AFTER IGNITION! YOU CAN
REACTIVATE THE LAMP ONLY 15—20 MINUTES AFTER ITS DEACTIVATION!
Draw "+" sign on a sheet of white paper sized as the stage and put the sheet on the stage. Put the 4x magnification objective lens
into the path of rays. Slide the knob (fig. 2, 1) into the casing and put the filter in the path of rays. Using knobs (fig. 1, 5 and 6),
open the field and aperture diaphragm. Install the ring (fig. 1, 27) to switch spectral beam splitting units in position No.3 ("B").
Observing into the eyepiece and moving the stage with the coarse focusing knob (fig. 2, 13), get the image of the paper sheet
surface. Moving the paper sheet on the stage surface, bring the "+" image into the eyepiece field center. Put the revolver seat
free of the objective lens into the path of rays.
Observing from the side (not into the eyepiece) on the paper sheet surface, move the collector with the knob (fig. 1, 7), to get
the sharpest image of the mercury-filled lamp discharge arc and its electrodes. Using knobs 10 and 11 (fig. 1), which regulate
the mercury-filled lamp position, put the discharge arc image onto "+" sign on the paper sheet surface (in the eyepiece field
center). Put the 4x and then 10x magnification objective lens into the path of rays. Observing into the eyepiece and moving the
collector with the knob (fig. 1, 7), achieve the most even illumination of the field.
Observation of objects
For investigation in the fluorescence light, the objects are exposed to treatment with special dyes (fluorochromes) having
specific spectral characteristics of absorption (excitation) and glow. In accordance with the fluorochrome used to treat the slide,
it is necessary to install one of five beam splitting units into the path of rays of the fluorescent illuminator given in table 1 of
subsection "Impinging light illumination system".
For example, for rather common treatment of slides using FITC, spectral unit No.3 ("B") is required, for Auramine — unit No.4
("V"), for stains glowing in the red spectral range, — unit No.2 ("G"). For DAPI and Hoechst stains, unit No.6 ("U") is used; when
working with this unit, the filter must be removed from the path of rays with a knob (fig. 2, 1).
Further do the following:
• install the object on the stage (fig. 2, 10) of the microscope;
• activate the objective lens with 10x magnification into the path of rays (it is recommended to start the process of focusing
from low or medium magnification objective lenses with sufficiently large fields and operating distances);
• focus the microscope by rotation of knobs (fig. 2, 12 and 13) for the sharp image of the object;
• cover the field and aperture diaphragm with knobs (fig. 1, 5 and 6);
• observing the object image, make sure that the image of the iris field diaphragm is located concentrically to the eyepiece
field (if the diaphragm is displaced, align it);
• if the field diaphragm image is displaced, put the image in the center of the field using knobs (fig. 2, 2);
• open the field diaphragm with a knob (fig. 1, 5) along the eyepiece field diameter so that edges of the iris diaphragm are
slightly beyond the eyepiece field;
• open the aperture diaphragm with a knob (fig. 1, 6), observing the eyepiece field, make sure that the illumination is quite
even, if necessary, adjust the collector focusing with a knob (fig. 1, 7);
• perform focusing on the object for observation with binocular tubes in the same manner as shown in subsection "Microscope
focusing for binocular observation" when working in transmitted light;
• start investigating the objects with short breaks in your work. To prevent slide fading, it is necessary to intercept the
luminous flux from the lamp with a knob (fig. 2, 1).
Microscope magnification and field diameter on the object
The total microscope magnification Г in process of visual observation with a binocular head is determined using the following
formula:
Γ β β Γ
= ob ∙ h ∙ eye
where βob — linear magnification of the microscope objective lens;
βh — linear magnification of the head equal to 1.0;
Гeye — visible magnification of the eyepiece.
The field diameter observed on the object, Dob mm, is determined using the following formula:
D
eye
D
ob =
β β
ob ∙ h
where Deye — diameter of the eyepiece field limited by the field diaphragm of the eyepiece, in mm.
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