Oil Immersion Operation

Objectives marked "Oil" are oil immersion type objectives (Typically these come in 50x and 100x). Objectives of this type require immersion oil to be applied between the specimen and the tip of the objective.

Air bubbles in the immersion oil will decrease image quality. Thus, it is important to keep these bubbles from forming during specimen preparation.

To check for air bubbles follow these steps:

1)Fully open the field diaphragm and aperture diaphragm.
2)Remove the eyepiece.
3)Examine the exit pupil (the bright round section)of the objective inside the eyepiece tube.

If you have trouble determining whether or not you are suffering from specimen degradation due to air bubbles using the method above, you can use the following method.

1)Attach a centering telescope. (optional accessory on clinical microscopes)
2)Look for air bubbles while turning the eyepiece section of the centering telescope to adjust focus.

How to remove air bubbles from your oil:

Turn the revolving nosepiece slightly to move the oil-immersion objective back and forth once or twice which will move the oil and disperse the bubbles.

or

Add more oil.
or

If the two above options fail, you will have to remove the oil and apply new oil.

Cleaning immersion oil:

Immersion oil is messy when it's not applied properly. Use as little oil as possible. You need just enough to make the connection between the tip of the objective and your specimen.

After use, thoroughly wipe off all the oil on the tip of your oil objective. (Also check to make sure you don't have cross contamination of your dry objectives in the event that the oil may have gotten on the non-oil objectives.)You should also thoroughly wipe off the condenser.

Cleaners:

Use petroleum benzine to wipe off immersion oil. For optimal results, you should follow up with a final cleaning using methyl alcohol.

Note: When using immersion oil during Fluorescent microscopy, you should use non-fluorescing immersion oil. This oil is typically marked NF on the bottle and can be purchased from authorized Nikon Microscope dealers.

Your microscope is an expensive investment. Keeping it cleaned and calibrated is good practice. We recommend you have your microscope serviced by a reputable microscope service company at least once a year if you operate in a clinical or research environment that uses oil immersion. You should also ask your service technician to give your staff a quick tutorial on how to use the microscope properly.