Question

Why should a swabbed sample never be rubbed across the slide during preparation?

1) Inadequate cell distribution
2) The sample will be too thick
3) Cell damage can occur
4) The sample will be too thin

Answer 1

Rubbing a swabbed sample harshly across a slide can cause cell damage and create uneven cell distribution, affecting staining and observation of cell morphology under a microscope.

Step-by-step explanation:

In microbiology, when preparing a slide with a swabbed sample, it is crucial to avoid rubbing the swab across the slide because this can cause cell damage. A gentle smearing technique is typically used to create a single layer of cells, which is essential for accurate microscopy. Rubbing the sample too harshly across the slide not only risks damaging the cells but also can result in an uneven distribution, making it difficult to discern cellular morphology and arrangement. If done too vigorously, some areas of the slide may have too thick a layer of cells, whereas other areas might be too thin, preventing consistent staining and reliable observation under a microscope.