module 2 - 2.1 microscopy Flashcards
why is a swan neck flask used?
so that the bacteria is unable to get in, neck is too long and thin
what is resolution?
the ability to see 2 objects that are close together
NOT CLARITY
why must cells be stained?
- to be able to see the internal organelles - increases contrast between cell components
- most cellular life has no colour
what is a dry mount?
- specimen viewed whole or cut into very thin slices (sectioning)
- placed on center of slide, cover slip on top
what would you view on a dry mount?
hair, pollen etc
what is a wet mount?
- specimen suspended in liquid like water or immersion oil
- cover slip placed from an angle
what would you view under a wet mount?
aquatic samples
what is a squash slide?
- wet mount prepared
- lens tissue used to gently press down the cover slip
what would you view under a squash slide and why?
root tips etc.
good for soft samples, avoids damage
what is a smear slide?
- edge of slide is used in a smear sample (creates thin, even coating on another slide)
- cover slip then placed over slide
what would you view under a smear slide?
cells in blood
what is single staining?
using a single stain in slide preparation
what is differential staining?
using 2 or more stains to increase the visual contrast between parts of a cell
what is the charge of the nuclei?
negative
what is the charge of methalin blue?
positive
