4th lecture : 22/9/14

Topic: History of microbiology and Microscopy

Notes:
1) The first person found the existance of microbes is Louis Pasteur.
2) Antonie Van Leeuwenhoek observed and described single-celled microorganisms as
    animalucules.
3) Robert Hooke improved Leeuwenhoek microscope and his famous observation on slides of cork.
4) Scientists proposed spontaneous generation - life arise spontaneously from non-living matter.
5) Spontaneous generation theory was supported by John Needham but not supported by Dazzaro Spallanzani.
6) Rudolf and Louis Pasteur changed the theory of spontaneous generation by biogenesis - living cell can arise only from preexisting living cells.
7) Pasteur's experiment: Filled broth into straight neck flask and s-shaped flask and both boiled and left to the air. Broth in straight neck cloudy while broth in s-shaped not cloudy. It proved that S-shaped trapped gened in curved neck and prevent them reaching the broth. Spontaneous generation was disproved by this experiment because broth s-shaped flask is not infected.
8) Koch's Pastules: Pathogen isolated from diseased host and let the pathogen grow in pure culture. Pathogen from pure culture injected into healthy animals.
9) Exception of Koch's Pastules: not all the microbe could be cultured in media, diseases caused by different pathogen may have similar symptoms. Same pathogen can caused several disease condition.
10) The goal of microscopy is to produce a magnified image and separate the details in image.
11) Bright-field microscope: staining is required, dark image against bright background
12) Dark-field microscope: staning is not required, produce bright image against dark background.
 13) Phase-constract microscope: staning is not required, dark image against bright background,
 14) Ultra-violet microscope: great resolution, shorter wavelength, the image displayed on screen.
 15) Fluorescence: bright image against dark background, specimen stained with fluorochromes
 16) Confocal image: 3D image
 17) SEM: 3D image, structure of cell smaller than 0.2um, resolving power 20nm, magnification 1000x to 10000x, study surface features of cell
 18) TEM: 2D image, structure smaller than 0.2um, resolving power 2.5nm, magnification 10000x to 100000x, study internal structure in thin section of cell

Activities: Quiz

My Own Exploration:
1) About Robert Hooke's study, he viewed on slides of cork anf he discovered empty spaces contained by walls. Therefore, he discovered building block of life and marked the beginning of cell theory.
2) Pasteurisation won't kill all the microbes, but only kill pathogen.
3) UHT is ultra high temperature.
4) Vaccine contains weak pathogen and it is used to activate immune response in our body.
5) BCG vaccine is Bacillus Calmette-Guerin vacine. It used tp treat tuberculosis and this vaccine is prepared from mycobacterium bovis.
6) We need to stained microbes because most of the bacteria are colourless and this makes us easier to examine the different part of thier body.
7) The smallest bacteria in the world is Mycoplasma.
8) Hela cell is a cell type in an immortal cell line used in scientific research.
9) Syphilis is a sexually transmitted infection causd by the spirochete bactellium Treponema Pallidum.

Relection on this topic:
I think history of microbiology is quite interesting. I salute with those scientists because they able to come out experiment to prove different kind of theory. I think microscopy is quite boring to me. I can't remember all the specific functions and characteristics of different kind of microscrope because I not yet use those microscopes.