Problems In Dark-Field Microscopy - Nikon ECLIPSE Si Instructions Manual

Fluorescence image is dark (even though the light source is turned on).
Problems
The diascopic illumination is not bright enough.
The room is too bright.
Weak contrast in fluorescence image
Problems
The objective or cover glass is dirty.
The immersion oil is emitting fluorescence.
The slide glass is emitting fluorescence.
5.1.5

Problems in Dark-field Microscopy

Incomplete field of view or no field of view seen
Problems
The dark-field slider is not at the click position (the
annular diaphragm is not in the optical path).
The objective's NA is not in this microscope's
supported range for dark-field microscopy.
No dark-field image seen
Problems
You are not using a dark-field slider.
The objective's NA is not in this microscope's
supported range for dark-field microscopy.
Chapter 5 Troubleshooting
Check Items
Adjust the illumination by turning the brightness control

knob close to the maximum position.
Dim the ambient light.

Check Items
Clean the lens.

Use a low-fluorescence oil (Nikon immersion oil)

specified by Nikon.
Use a non-fluorescent glass slide.

Check Items
Move the slider until it clicks.

Bring the dark-field objective into the optical path.

Check Items
Mount a phase contrast slider and bring the

appropriate position into the optical path.
Bring the dark-field objective into the optical path.

114
Reference
3.2.1
3.10.3
Reference
3.3.1
3.4.2
―
Reference
2.5
4.2.5
3.10.4
Reference
2.5
4.2.5
3.10.4