Question

Prior to staining, smears of microorganisms are heat-fixed in order to ________

1) allow eventual visualization of internal structures.
2) ensure removal of dust particles from the slide surface.
3) attach it firmly to the slide.
4) create small pores in cells that facilitates binding of stain to cell structures.

Answer 1

3) attach it firmly to the slide. Smears of microorganisms are heat-fixed prior to staining to attach them firmly to the slide and prevent them from washing away. Heat fixing also kills microorganisms and preserves the integrity of their cellular components for observation.

Step-by-step explanation:

Prior to staining, smears of microorganisms are heat-fixed in order to attach it firmly to the slide. Heat fixing allows the biological material to become more or less permanently affixed to the slide's glass surface, preventing the bacteria from washing away during the staining steps. Additionally, fixation kills microorganisms, stopping their movement and metabolism while preserving the integrity of their cellular components for observation.