Microbiology Week 4

   Assalamualaikum and good afternoon eveyone that reading my blog now.... 😃😃😃😃. This week is my forth week of microbiology class. I feel like it is my first class but actually my forth class with Dr Wan... You know time flying so fast. I would like to share you what I learned in the forth week of microbiology class with my spotting lecturer Dr Wan. Usually after my microbiology class, I feel so tired and sometimes I a bit stress because a lot of works and reseach have to do. That was as usual because I as a microbiology student I have to do more reasearch to know and find the types of microoorganisms. Like a scientist huhuhu 😍😍😍. I feel stress because Im not yet adapt the changes in university. I think it will takes a bit more time to adapt the changing because now only my enter to the degree. But for sure oneday i will change and become a good and profesional scientist .😎😎😎 So on wednesday, Dr Wan taught us about electron microscope and on friday we all had group discussion about the classification of organisms. Group discussion is like in one group we have to separate the topic among with our group members and understand about the topics. Then who are got the same topics to be discuss they are will combine and make a group. They discuss about what they are understand and do more research. Afterthat, only two people are in the group and the rest of all can go to another topic groups and the another group members will explain about what they are understand about their topics. The discussion a quiet fun and we all enjoyed but we does not have enough time to go to more groups but Dr Wan said we will study again in next week.This week for classifications of organisms are short details. After Dr Wan explain it then most probably next week I will share more about classifications of organisms. So, Im going to share the information about electron microscope.

              Electron Microscope

An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100, 000 times shorter than that of visible light photons, electron microscopes have a resolving power than light microscopes and can reveal the structure of smaller objects. Electron microscopes have electron optical lens systems that are analogous to the glass lenses of an optical light microscope.The similarity of scanning electron microscope (SEM) and transmission electron microscope (TEM) is are both structures smaller than 0.2 micrometer. The differences between of SEM and TEM are SEM produces a realistics 3D image of specimens's surface features but produces 2D image. The magnification of SEM is 1000X to 10,000X but in TEM are 10,000X to 100,000X. The resolving power for SEM is 20 nm but in TEM is 2.5 nm. SEM is to study the surface features of cells and viruses but TEM is to examine viruses or the internal ultrastructure in thin sections of cell. Electron Cryotomography is rapid technique provides way to preserve native state of structures examined in vacuum. Images recorded from many different directions to creates 3D structures.

                                                                         

                  

Scanning Electron Microscope

view under electron microscope

         

Preparations of specimens for light microscopy 

Preparations of specimens for light microscopy are wet mount and smears. Smears-steps involve are preparing smears, fixation, and staining.Fixation is a preserves internal and external structures and fixed them in position. Stain is a salt composed of a positive and negative ion, one of which is colourful this will called the chromophore. Stain make internal and external structures of cell more visible by increasing contrast with background. There are three types of staining which are simple staining, differential staining and special staining. In differential staining have gram staining and acid-fast staining. In special staining have negative staining, endospore staining and flagella staining.

gram stain

acid-fast staining 

negative staining

endospore staining 

flagella staining 

Classification of organisms 

Taxonomy is a arrangement into groups based on mutual similarities. There are three interrelated parts in the taxonomy which classification, identification and nomenclature. Classification is the arrangement of organisms into groups or taxon based on mutual similarity or evolutionary relatedness. Identification is the process of discovering and recording the traits of organisms. Nomenclature is a assignment of names to taxonomic groups in agreement with published rules.Strain is a subgroup of species with one or more characteristics that distinguish it from other subgroups of the same species. Different ways to describe strains within a species which are biovars, morphovars and serovars. Phylogenetic classifications is a natural systems based on evolutionary relationships and direct comparison of genetic material and gene products.

Methods of classifying and identifying microorganisms

Methods of classifying and identifying microorganisms are morphological characteristics, differential staining, biochemical tests, serology, phage typing, fatty acid profiles, DNA base composition,DNA fingerprinting, nucleic acid hybridization. Methods use to classify and identify microorganisms after various analyses which are dichotomous keys and cladograms.