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

Option (3), Heat fixing microorganism smears prior to staining helps firmly attach the cells to the slide and kill the organisms, preserving their structure for observation under a microscope.

Step-by-step explanation:

Heat Fixation in Microorganism Smear Preparation

Prior to staining, smears of microorganisms are heat-fixed in order to attach it firmly to the slide. This is essential in microbiology for the preparation of cell samples for light microscopy. Heat fixing secures the biological material to the glass surface, makes the cells adhere to the slide, and minimizes the loss of sample during the staining process.

It also serves to kill the microorganisms, which prevents any further movement and metabolism, preserving the structures of the cells for observation under the microscope. Upon heat fixing, various staining techniques, such as Gram staining or using safranin, can then be applied to the sample for enhanced visualization of the microorganisms.