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 https://www.youtube.com/watch?v=DuFb8A5_iD8 https://www.youtube.com/watch?v=ZjnW9CqrAJI https://www.youtube.com/watch?v=-tzNsaCrUMw For stool investigation • https://www.youtube.com/watch?v=aVe2oSE _da8 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 number! Lab IV: Microscopy and staining of parasites 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 observed • What are the objectives used and for what purposes • Please write your name and surname and your number! • Thank you
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