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8.10 Use of fluorescence
Operate on the main switch placed in the rear
side of the microscope. Setting on “I” turns on
transmitted light, setting on “II” turns on fluore
-
scence.
Setting on “O” turns off the microscope. (Fig.
28)
Move the filter selector in the “B” position (Fig.
29) to insert the fluorescence filter in the light
path. Move the selector in the center to work
with brightfield transmitted light.
Unlike a mercury lamp system, B-290LD LED
illumination doesn’t need any power-up time
for heating, and can be used immediately after
switching on. Also, the LED source is pre-alig
-
ned in factory and doesn’t need any alignment
operation.
Focus on your sample, and adjust the light
intensity as needed through the brightness
adjustment knob. In order to improve the
darkness of the background (thus improving
contrast), it is strongly suggested to put the put
a dark cover on the light exit at the base of the
microscope.
FILTER
NAME
EXCITATION
FILTER
DICHROIC
MIRROR
BARRIER FILTER
APPLICATIONS
B
460 - 490 nm
505 nm
515LP nm
• FITC: fluorescent antibodies
• Achridine orange DNA - RNA
• Auramine
8.11 Use of the polarizer (optional)
1.
Remove the specimen from the stage.
2.
Looking inside the eyepieces, rotate the po
-
larizer until the darkest position is achieved.
3.
Once the dark is achieved (“extinction” or
“Crossed Nicol” position) it is possible to
begin the observation.
Fig. 28
Fig. 29
