E-Portfolio: Microbiology - Week 7

What is up, people!

This week, we learned on internal structure and its function of a prokaryote with Dr. Wan

Courtesy: https://www.shmoop.com/biology-cells/prokaryotic-cells.html


I am actually quiet interested with plasmid, a small structure, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance. Plasmids have a wide range of lengths, from roughly one thousand DNA base pairs to hundreds of thousands of base pairs. When a bacterium divides, all of the plasmids contained within the cell are copied such that each daughter cell receives a copy of each plasmid. Bacteria can also transfer plasmids to one another through a process called conjugation using sex pili.

For our experiment this week, we had done Gram staining and Acid-fast staining.

The Gram stain is the most important staining procedure in microbiology. It is used to differentiate between gram positive organisms and gram negative organisms. Hence, it is a differential stain. Gram staining involves a four-part process, which includes crystal violet (the primary stain), iodine (the mordant), a decolorizer made of acetone and alcohol and safranin (the counterstain).

The acid-fast stain is a differential stain used to identify acid-fast organisms such as members of the genus Mycobacterium .Acid-fast organisms are characterized by wax-like, nearly impermeable cell walls; they contain mycolic acid and large amounts of fatty acids, waxes, and complex lipids.  Acid-fast organisms are highly resistant to disinfectants and dry conditions.

These are few pictures of stained microbes under oil immersion.

Mycobacterium smegmatis and Staphylococcus aureus stained with Acid-fast staining under microscope.

Bacillus cereus with endospores stained with Gram staining method under microscope 







Ulasan

Catat Ulasan

Catatan popular daripada blog ini

E-Portfolio BMY3201 - Experiment 2 & 3

Imej
27th September 2017 This week I learned on several techniques for microbes culturing that involve plating, using nutrient broth and agar, also using gelatin. There are few types of plating such as streak plate method, spread plate method and pour plate method. I managed to practices on doing streak-plate and spread-plate method. For streak-plate method, I learned on how to use inoculation loop by streaking on the agar plate surface. It is quite hard but I think I can improve my techniques in the future. For spread-plate method, we basically use bent glass rod to spread the microbes on the surface of agar plate, but for this technique we use alcohol to sterilize the glass rod which is actually quite harmful as we also use bunser burner for the same experiment. We must practice proper precaution and handle the experiment carefully to avoid any accident. Here is some pictures from this week experiment : Microorganism sample from toilet sink E. coli streaking culture
Baca lagi

E-Portfolio Microbiology II Week 8

Imej
Hello all! How are you guys doing ? So, this week we had learnt something new that happens to be in the branches of Microbial Genetics. As we all know, Microbial Genetics can be separated into several category that includes replication, transcription, translation and recombinant. This week, we learnt more on replication and transcription from Dr Suriana.  Basically,  DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell. The replication process relies on the fact that each strand of DNA can serve as a template for duplication. DNA replication initiates at specific points, called origins, where the DNA double helix is unwound. A short segment of RNA, called a primer, is then synthesized and acts as a starting point for new DNA synthesis. An enzyme
Baca lagi