what is the function of the oil when using the oil immersion objective?

Question

thanks

Answer 1

as what we have studied in our subject (microbiology), the oil serves as part of the specimen. the oil and the glass has the same refractive index so it will give you better vision of the specimen.

hope i had helped you.

Answer 2

bonjette is correct.
It allows better resolution, particularly noticeable at high magnification, because the focussing does not have to allow for the change in refractive index between glass and air and glass again, as it does with a "dry" image.