Viewing Bacteria Under Oil Immersion
• Using oil immersion:
1. Place slide on mechanical stage (make sure
side of slide with smear is facing up). 10x
2. View smear with low power (10x) (cant see
much, but at least get the smear to appear
crisply in focus).
3. Protect your high dry objective lens
(40x) with finger cot.
4. Place a drop of immersion oil directly onto
each bacterial smear.
5. Switch to oil immersion lens (100x) and
be sure not to move the focus or stage.
6. ONLY USE FINE FOCUS
7. You should be able to see individual
bacteria cells (either round or rod shaped,
depending on the type of bacteria).
8. When done, use lens paper to clean up
your lenses and stage.
9. Store scope with shortest, scanning lens
(4x) pointing sown and stage lowered as
far as it will go.
• Don’t EVER use coarse focus when
working with high dry or oil immersion.
• Remember PARFOCAL!!
This instruction sheet is from the Science Prof Online - Virtual Microbiology Classroom.