Content Status
Type
Linked Node
Oil immersion and focusing
Learning Objectivesself explanatory
H5Content
Content
The following are the measures to be kept in mind when adding immersion oil to the slide:
- Before adding immersion oil to the slide, ensure that the smear is facing upwards (Figure 1).
Figure 1: Slide should Face Upwards when Mounted on the Microscope Stage
- Add a drop of immersion oil, using the applicator (dropper bottle).
- The drop must fall freely onto the smear, so that the oil applicator does not touch the slide and get contaminated (Figure 2).
Figure 2: Oil Dropped onto Slide with an Applicator
- Mount the slide on the microscope and use the 10X objective lens to focus the smear, scan and look for mucoid material.
- Carefully rotate the 100X objective lens over the slide, adjust, sharp focus and observe under immersion oil.
Do’s and Don’ts:
- The 100X objective is the only lens requiring immersion oil.
- Keep the immersion oil away from other lenses.
- Use a good quality immersion oil.
- The immersion oil must have a medium viscosity and a refractive index (RI) greater than 1.5.
- Never allow the oil applicator to touch the slide.
- Do not use cedar wood oil diluted with xylene as it leaves a sticky residue on the lens and destroys the lens over time.
Resources
- Guidelines for Laboratory Consumables, Central TB Division, 2019.
- Laboratory Diagnosis of Tuberculosis by Sputum Microscopy, GLI Initiative.
Kindly provide your valuable feedback on the page to the link provided HERE
LMS Page Link
Content Creator
Reviewer
Target Audience
- Log in to post comments