Page 738 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

G Te Microscope

APPENDIX

EQUIPMENT AND SUPPLIES USE OF THE MICROSCOPE

1. Microscope A microscope is a elicate instrument. Follow the proce ural

2. Lens paper step in exact or er.

3. Kimwipes

4. Immersion oil

Step Procedural Steps

1 Remove the microscope dust cover and clean the lens of the objectives (see below).

2 Turn on light source. Rotate the low power, for example, 10×, objective lens slowly until an audible click is heard.

Note: Always begin initially focusing with the low power objective.

3 Look at the microscope from the side to increase the working distance as far as possible with the coarse adjustment.

4 Put on gloves as directed. Select a specimen slide and place on the microscope stage. Secure with clamp on the

stage.

5 Center the slide on the stage by rotating the stage knobs located under the stage.

6 On the ocular, turn the diopter ring to the middle of the adjustment range. While looking through the right eyepiece,

slowly turn the coarse adjustment to bring the specimen into focus. Once in focus, use the ne adjustment knob to

make a sharper image adjustment.

7 While looking through the left eyepiece, turn the diopter adjustment ring to focus the specimen.

8 Adjust the interpupillary distance of the eyepieces until both left and right elds of vision coincide completely. The

image should appear as one single eld with a sharply focused image. The image should remain in sharp focus if

either eye is closed.

Note: Lift out one eyepience and adjust aperture diaphragm to about 3/4 full. Speci c adjustments are 0.25 for 10×, 0.65 for

40×, and 1.3 for 100×. Replace eyepiece.

9 After the specimen slide is in focus, open the iris diaphragm in the substage condenser to its widest adjustment. Set the

light source intensity control to about 2/3 maximum output. A blue lter may be needed to reduce yellow emissions from

the light source.

10 If the condenser has a swing out lens, position this lens in the light path.

11 Lower the condenser and close the eld iris diaphragm. Raise the condenser until the image of the circle of light is

in sharp focus.

12 Center the eld iris diaphragm by manipulating the two centering screws on the compensating lens.

Note: To check, open the eld iris diaphragm until its image touches the perimeter of the eld of view. If the image is not

precisely in the eld of view, center again.

13 Open the eld iris diaphragm until the edge of the leaves disappear from your eld of vision.

14 Select and position the objective lens of choice. Adjust the iris diaphragm until the appropriate amount of light is

available. The amount of light is also controlled by the light source.

Note: Less light is needed for 10× and the most amount of light is needed when using the oil immersion (100×) objective

lens. The amount of light needs to be adjusted each time a new objective lens is selected.

15 Use the ne adjustment knob to refocus to the sharpest image. With parfocal objectives, once an image is in focus with 10×,

it will remain in focus when higher power objectives, for example, 40× or 100×, are selected.

If 100× objective lens is selected, move the slide slightly sideways and place a drop of immersion oil direct on the

slide over the area to be observed. Return the slide to the appropriate viewing area.

Caution: Always begin focusing with the low power objective, for example, 10×.

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