Chapter 2B

Download
Share  Add to  Flag Embed
Views:
 
Category: Entertainment
     
 
License:   All Rights Reserved

Presentation Description

No description available.

Comments

 

By: juggernautt (12 month(s) ago)

good presentation

Presentation Transcript

Announcements : 

Announcements 9/16/2010 1 Group Tutoring: Pre-course survey on Blackboard: Lab Worth a 10 pt quiz Lab begins this week… read material in advance. Safety glasses & closed toed shoes.

Microscopy: : 

Microscopy: Chapter 2 part B Staining Specimens and Different Types of Microscopes 9/16/2010 2

Staining Bacterial Specimens increases contrast! : 

Staining Bacterial Specimens increases contrast! 9/16/2010 3 No staining + Staining Staining…… Increases visibility provides diagnostic info & identity. Why?

Specimen Preparation: : 

Specimen Preparation: 9/16/2010 4 Fixation: specimen is preserved & attached to a slide. Heat fixation– preserves morphology Chemical fixation- preserves morphology & internal structure.

Chemical basis behind staining: : 

Chemical basis behind staining: 9/16/2010 5 Stains are composed of 1. A chromophore- color 2. Charge (salt)- Basic dyes*- (+) charge (cationic). Methylene blue / Crystal violet / Safranin Acidic dyes- (-) charge (anionic). Acid Fuchsin / Eosin / india ink Often used as a negative stain!

Slide 6: 

9/16/2010 6 Alcamo’s Funamentals of Microbiology Fig. Figure 03.11ab: Important staining reactions in microbiology.

Types of staining procedures : 

Types of staining procedures 9/16/2010 7 1. Simple Stains- single staining agent in an aqueous / alcohol solution. Size / Shape / Cell Arrangement

Slide 8: 

9/16/2010 8

Slide 9: 

9/16/2010 9 2. Differential stains- Utilizes > 1 staining procedure: Distinguishes between different types of bacteria. Cell wall: Gram stain & Acid fast staining The Gram stain- “Hans Christian Gram (1853-1938)” Clinical Microbiology.

The Gram stain: : 

The Gram stain: 9/16/2010 10 Gm + bacteria = purple Gm – bacteria = pink Fig. 2.14, p. 24

Slide 11: 

Acid Fast Staining- (Nester Fig. 3.15, p. 51) bacteria containing waxy lipids in cell wall stain acid fast (Mycobacterium sp & Actinomycetes). 1o stain- carbolfuchsin+ heat: Decolorize- acid alcohol Counterstain- methylene blue 9/16/2010 11

Slide 12: 

9/16/2010 12 Fig. 2.13, p. 23

Slide 13: 

9/16/2010 13 3. Special Stains- stains specific structures inside/ outside of the bacterial cell.

Slide 14: 

9/16/2010 14 Fig. 3.18, nester

Other Types of Microscopes: : 

Other Types of Microscopes: 9/16/2010 15

Slide 16: 

9/16/2010 16 Phase Contrast Microscope- Exploits different refractive index between specimen & surroundings. No staining. Prokaryotes: Endospores/inclusions/motility

Slide 17: 

9/16/2010 17 Fig. 2.7

Slide 18: 

Dark Field Microscope- Staining not needed. Eukaryotic cells & larger bacteria. Borrelia & Treponema (spirochetes) 9/16/2010 18

Slide 19: 

9/16/2010 19

Slide 20: 

Fluorescence Microscope- 9/16/2010 20 UV light source. Fluorochromes: Fluorescent dyes Immunofluorescence- fluorescent antibody conjugates. Figure 2.11

Slide 21: 

9/16/2010 21

Slide 22: 

9/16/2010 22 Neisseria meningitidis, group C, in spinal fluid. Clinical Microbiology: - diagnostic

Fig 2.12, p. 21 : 

Fig 2.12, p. 21 CTC binds viable cells (green). C) Fluorescent labeled Ab bound to S. pyogenes. 9/16/2010 23 B) Modified Acid Fast- (Auramine & rhodamine)

Slide 24: 

Prokaryotic cell division protein FtsZ http://www.umass.edu/microbio/chime/pipe/ftsz/present/ 9/16/2010 24 Fluorescence image (following deconvolution) of FtsL::GFP chimera protein localized as a ring in a living, dividing E. colicell. FtsL and other cell division proteins localize to the Z ring and are required for proper septum formation in E. coli.

Electron microscopy : 

Electron microscopy 9/16/2010 25 Utilizes electromagnetic lenses & electrons. Magnifies 10,000 – 100,000 times Resolution increases 1000 fold (~0.5 nm).

Slide 26: 

9/16/2010 26

Slide 27: 

9/16/2010 27

Slide 28: 

9/16/2010 28 Fig. 2.19 Negative stain of T4 phage: Specimen spread out in a thin film with phosphotungstic acid or uranyl acetate. Proteus mirabilis shadowing: - Platinum or heavy metals. TEM

Slide 29: 

9/16/2010 29 Freeze etching: Provides information on shapes of structures. Frozen in liquid nitrogen & fractured. Stained with platinum & carbon.

SEM: : 

SEM: 9/16/2010 30 Fig. 2.22

Confocal Scanning Laser Microscopy: : 

Confocal Scanning Laser Microscopy: 9/16/2010 31

Ch. 3- Prokarotic Cell Structure & Function : 

Ch. 3- Prokarotic Cell Structure & Function 9/16/2010 32 Overview of Cell Structure Cell Membranes Cell Wall Gm + & Gm- Cell Wall Structure Gm- Outer Membrane Other Cell Wall Structures External Cellular Structures Internal Cellular Structures.