Question

#7.

MOURE 2.1 Phase-contrast microscopy. B - D readed by p o dbye eople ) PROCEDURE Wol-Mount Technique 1. Suspend the infusions by string or shaking them carefully. Using a Pasteur pipette transfer a very small drop of one day inson to a slide, or transder a loopt using the inoculating loop as demonstrated by your instructor Handle the coverstip carefully by its edes, and place it on the drop Gently press on the coverslip with the end of a pers cilor loop handle 4. Place the slide on the microscope stage and ob- serve it with low power (OX). Adjust the iris dis phragm to admit a small amount of light. Concen trate your observations on the larger, more rapidly moving organisins. At this magnification, bacteria are barely discernible as tiny dots. FIGURE 2.2 and Figure 34.5 on 275 may help you to identity some of the microors .) Examine the slide with the high-dry lens (40X to 45% increase the light and focus carefully. Some microorganisms are motile, where others exhibit Brownian movement. After recording your observations, examine the slide with the oil immersion lens. Bacteria should now be manified sufficiently to be seen 7. If you want to observe the motile organisms fur- ther place a drop of alcohol or Gram's odine at the edge of the coverslip, and allow it to run under and mix with the infusion. What does the alcohol lodine do to these organisms ) -

Answer 1

It generally used to check the strain whether it is gram positive or gram negative where alcohol provides colour differentiation.adding alcohol would give different colour to different strain in case of gram positive due to presence of peptidoglycan it stain and colour purple while in case of gram negative it turns pink.