Chapter 3 Operation
3.14 PFS (Perfect Focus System) Operation
82
Supported specimens
The PFS function can be used with any specimen that satisfies the following conditions.
Cells attached to the cover glass of a glass-bottomed dish.
• Cover glass Thickness: 150 to 180 μm (No.1S)
Refractive index: 1.5
• Culture solution Depth: 3 mm or greater
Refractive index: Approximately 1.33
Figure 3-45 PFS overview
Unsupported specimens
In-focus observation with the PFS may be difficult on the following specimens, for reasons such as weak IR
reflectivity or excessive scattered light.
1. Fixed specimens
In general, fixed specimens are filled with an encapsulating medium. Due to the high refractive index of
this medium, the difference in the refractive index between the cover glass and the specimen is
decreased. Thus, the amount of reflected light may be insufficient for surface detection.
2. Sliced specimens
Sliced specimens are thick, and scatter a large amount of light. This makes it difficult to capture the
relatively small amount of reflective light from the boundary surface.
3. Specimens with large amounts of scattered or reflected light
For the same reason as for the sliced specimens, non-sliced specimens that scatter a large amount of
light are also unsupported.
4. Cells attached to a container with a glass bottom thicker than 170 μm
When using a dry objective with a specimen in thick glass, the boundary surface may not be detectable
due to insufficient offset. (The boundary surface may be detectable if using an oil immersion objective.
However, use of No.1S cover glass is recommended.)
5. Plastic dishes
The use of plastic dishes is not recommended, as their boundary surfaces are not as precise as those of
glass.
6. Dirty cover glasses (oil stains, dust)
The PFS maintains focus by detecting the boundary surface of the cover glass. Contaminations on the
cover glass will degrade the precision of the detection. Be sure to clean the cover glass before use.
Boundary surface
(Water/oil immersion)
Boundary surface
(Dry)
Refractive index
Oil: 1.514
ir: 1.0
Water: 1.33
Cover glass: approx. 1.5
Culture solution: approx. 1.35
t = 165 ±15 μm
(Standard: No.1S)
t
≥ 3 mm
To Next Page
Loading...
Need help?
General
