LabIII: Microscopy and staining of bacteria (Dry Lab)


LabIII: Microscopy and staining of bacteria (Dry Lab)
LabIII: Microscopy and staining of
parasites:(Dry Lab)
- preparation of blood smears
- parasitic stool investigation
Immersion objective
• 100x objective
• Immersion oil
• For fixed and stained material
– Giemsa stained blood smear
– Acid fast stained oocyst
Acid-fast stain
Oocysts in stool smears stained with modified acid-fast stain:
A Cryptosporidium sp. B Cyclospora cayetanensis C Cystoisospora belli
Giemsa stained blood smear
Ring with double chromatin dot
Schüffner's dots
• 10x
• 40x objective
• Direct wet-mount investigation
• For slide covered investigations of concentrated stool
stained with lugol solution containing iodine
Immersion objective
Principle of immersion microscopy
Principle of immersion microscopy
• Path of rays with immersion medium (yellow)
(left half) and without (right half). Rays (black)
coming from the object (red) at a certain angle
and going through the coverslip (orange, as
the slide at the bottom) can enter the
objective (dark blue) only when immersion is
used. Otherwise, the refraction at the
coverslip - air interface causes the ray to miss
the objective and its information is lost.
For investigation blood
For stool investigation
Concentration :DiaSys_parasep
For Lab report III
• You will draw the steps of Giemsa stain
• What is it used for?
• What is used for staining stool for parasitic
infection after concentration?
• Please write your name and surname and your
Lab IV: Microscopy and staining of
You will be given
• One alcohol fixed slide to be stained by you by
Giemsa stain
For lab report IV:
• You will draw what
you have seen
• And write down
what you have
• What are the
objectives used and
for what purposes
• Please write your
name and surname
and your number!
• Thank you