What is the purpose of oil immersion when using a microscope?

Last Update: April 20, 2022

This is a question our experts keep getting from time to time. Now, we have got the complete detailed explanation and answer for everyone, who is interested!

Asked by: Gregory Herman
Score: 4.6/5 (21 votes)

Immersion Oil contributes to two characteristics of the image viewed through the microscope: finer resolution and brightness. These characteristics are most critical under high magnification; so it is only the higher power, short focus, objectives that are usually designed for oil immersion.

What is the function of immersion oil?

Immersion oil increases the resolving power of the microscope by replacing the air gap between the immersion objective lens and cover glass with a high refractive index medium and reducing light refraction.

How is oil immersion used in microscopy?

Using immersion oil

Place a drop of immersion oil on the cover slip over that area, and very carefully swing the oil immersion lens into place. Focus carefully, preferably by observing the lens itself while bringing it as close to the cover slip as possible, then focusing by moving the lens away from the specimen.

What is the purpose of the immersion oil that is used with the 100x objective?

The 100x lens is immersed in a drop of oil placed on the slide in order to eliminate any air gaps and lossof light due to refraction (bending of the light) as the light passes from glass (slide) → air →​​​​​​​ glass (objective lens). Immersion oil has the same refractive index of glass.

Why immersion oil is used when observing a specimen when is it used?

In light microscopy, oil immersion is a technique used to increase the resolving power of a microscope. This is achieved by immersing both the objective lens and the specimen in a transparent oil of high refractive index, thereby increasing the numerical aperture of the objective lens.

How To Use Immersion Oil

37 related questions found

Do you use a coverslip with oil immersion?

Oil-immersion objectives should be used with coverslip-thick glass (or optically equivalent plastic) to achieve their best imaging performance. ... This can be easily done by turning the glass slide over and viewing the cells through the 1-mm thick slide, with the coverslip facing away from the objective.

What would happen if you use water instead of immersion oil?

Under ideal imaging conditions, the best optical performance is achieved by use of immersion oil that exactly matches the refractive index of the objective front lens element and cover glass. Substitution of water or another immersion medium having a higher or lower refractive index degrades this performance.

What kind of oil is used in oil immersion objective?

Only use oil which is recommended by the objective manufacturer. For many years, cedar wood oil was routinely used for immersion (and is still commercially available). Although this oil has a refractive index of 1.516, it has a tendency to harden and can cause lens damage if not removed after use.

Does oil immersion increase magnification?

Oil Immersion Microscopy increases the refractive index of a specimen when used properly. With limited disadvantages, slides prepared with oil immersion techniques work best under higher magnification where oils increase refraction despite short focal lengths.

What is the best way to clean immersion oil from the microscope lens?

6 Tips to Properly Clean Immersion Oil off Your Objectives
  1. Clean off the oil immediately after using it. ...
  2. Use the eyepiece to inspect any dust on the objective. ...
  3. Remove any dust or dirt with a blower. ...
  4. Fold a piece of lens paper to create a point. ...
  5. Soak the lens paper in a suitable solvent.

How much does oil immersion magnify?

The oil immersion objective lens provides the most powerful magnification, with a whopping magnification total of 1000x when combined with a 10x eyepiece.

What is the highest magnification you should focus before use oil immersion technique?


Why cedar wood oil is used in oil immersion?

The disadvantageous properties of cedarwood oil are: high absorption of blue and UV light, yellowing with age, a tendency to harden on lenses due to uneven volatility, acidity, and changing viscosity (diluting with solvent changes the index and dispersion).

What do you mean by oil immersion lens?

A special lens with oil placed between the lens and the object being visualized. This eliminates a layer of air between the microscope slide and the lens, producing a clearer image than if the oil were not used.

Can you use immersion oil with 40X objective?

Never turn your nosepiece back to the 40x objective when using oil or you will get oil all over that objective. Immersion oil should never be put on any other objective than the 100x!

How does oil immersion improve resolution?

Key takeaways. The microscope immersion oil decreases the light refraction, allowing more light to pass through your specimen to the objectives lens. Therefore, the microscope immersion oil increases the resolution and improve the image quality.

When cleaning immersion oil from a 100X lens what should be used?

If you are using a 100x objective with immersion oil, just simply wipe the excess oil off the lens with a kimwipe after use. Occasionally dust may build up on the lightly oiled surface so if you wish to completely remove the oil then you must use an oil soluble solvent.

What is the difference between Type A and Type B immersion oil?

Immersion Oil Selection Guide

Type A, at 150 centistokes, reduces any tendancy to trap air, especially helpful to beginning students. Air bubbles cause image degradation. Type B, at 1250 cSt, is thick enough for viewing multiple slides with one application. This saves time during batch processing.

What is the NA value of oil immersion objective lens?

In practice, however, most oil immersion objectives have a maximum numerical aperture of 1.4, with the most common numerical apertures ranging from 1.0 to 1.35.

What can be used instead of immersion oil?

Methyl salicylate, also called oil of wintergreen, has been found to be an excellent substitute for commercial immersion oil.

What serious and costly mistake can you make when using an oil immersion objective?

In the short term, the oil will cause the objective to look blurry or 'broken' which leads to a service call for a simple problem. However, oil left on any objective (including the 100x) will eventually seep into the lens over time, rendering it useless. This can be a costly mistake.

Why should microscope lens not be touched?


Handling & Cleaning: Never touch the lenses with your fingers. Your body produces an oil that smudges the glass. This oil can even etch the glass if left on too long.

Why is immersion oil used with the 100X objective quizlet?

Immersion oil has the same refractive index compared with that of glass. This prevents light loss due to diffraction. Oil immersion should be used between the slide and 100x objective lens, this is a special oil that has the same refractive index as glass.