Experimet A : The microscopic measurement of microorganisms

-
     Assalamualaikum and a very good morning everyone.... The experiment I did in this week (fifth week) is about the how we measure the microorganisms. Because microorganisms are too tiny and we cant see in our naked eyes. As usual Dr. Adelene taught us how to measure. But majority in my class were not understand what Dr. Adelene said including myself 😂😂😂 . Later on, our demostrated also taught again what Dr.Adelene said. The demostrated came to every group and taught and shown us how to measure it. Encik. Zainudddin also gave some demo. Firstly, I opened the ocular (eyepiece lens) and put the ocular micrometer inside the ocular lens. Then, I was placed the stage micrometer on the stage and adjusted the coarse-adjustment knob until I got found the two scales. Next, I superimposed on the each other of the scales and calibrated it. This week experiment was simple and will be more focused. I got learned something new in this week how to measure the microorganisms. Because when I'm in secondary school or in matriculation, I never learnt about it. I just got learned how to saw the microorganisms under microscopes only. Now I'm as a microbiology student , I have study more even more about microorganisms. So, I'm going to share the informations about this experiment which is the microscopic measurement of microorganisms.

   Measurement of the dimensions of microorganisms is done under microscope with the two micro-scale called "micrometers". Both the micrometers have microscopic graduations etched on their surfaces. The ocular micrometer which is placed inside the eyepiece, is a glass dics graduation etched on its surfaces. The distance between this graduations will vary depending on the objective being used, which determines the size of the field. This distance is determined by using a stage micrometer is a glass slide with etched graduation that are 0.01mm or 10 micrometers apart. The calibration procedure for the ocular micrometer reqiures that the graduations on both micrometers be superimposed on each other by rotating the eyepiece. The number of ocular divisions coinciding with the number of stage divisions is found out. After the calibration, the stage micrometer is removed and the microbe, whose dimensions are to be measured, is placed on the stage on a slide and focused. Then, the number of ocular divisions occupied by the microorganism is counted. By multiplying, this number of divisions with the calibration factor, the size of the microbe is determined.


    It is possible to measure the size of microbes by directly observing them on a stage micrometer. This would avoid calibration and calculations. But the stage micrometer is a standard scale, which is costly because of the micro etchings on it. If used frequently for direct observations, its etchings get worm away. Moreover, the etchings on the stage micrometer are more widely spaced than those on the ocular micrometer. Thus, the dimensions cannot be precisely determined with a stage micrometer. That is why it is never used for direct measurement.

Comments

Post a Comment

Popular posts from this blog

experiment 4: Microscopic examination of stained cell preparation and experiment 5: Microscopic examination of living microorganisms using a Hanging-Drop Preparation or a Wet Mount

-
Image
 Assalamualaikum and good morning everyone..... how are you guys?.😃😃😃.. so now Im going to share with you about my experience when I did my forth anf fifth experiment which are forth experiment about Microscopic examination of stained cell preparations and fifth experiment about Microscopic examination of living microorganisms using a Hanging-drop preparation or a Wet mount. First and foremost, after I was entered to the class, DR Adelene taught about the parts of microscope, different types of microscopes, the function of each parts of microscopes.  DR also talked about the magnifications, resolving power or resolution and so on. The experiment that we did this week are more interesting than last week because we saw microorganisms under microscope.😁😁😁 Mr Hussain also taught us how to clean the objective lens, how to hold the microscope and gave some demo. For the fifth experiment, Mr Zainuddin was explained about the experiment and taught us how to do the experiment. Fo...
Read more

Experiment 1: Culture Transfer Techniques

-
Image
  First microbiology lab experiment class with DR. Adelene Song... Assalamualaikum.... For my first microbiology lab class with DR. Adelene Song was actually fun and interesting because I got learned some techniques how to transfer of microorganisms for subculturing, how to correctly sterilize inoculating instruments in the flame of in bunsen burner. MR.Hussain  was taught us the concept of aseptic technique and the procedures necessary for successful subculturing of microorganisms. DR.Adelene also taught us how to write a proper lab report and the laboratory skills. It is very helpful to us.  Experiment 1: Culture Transfer Techniques    Microbiology is the study of microscopic organisms, those being unicellular (single cell), multicellular (cell colony), or acellular(lacking cells). Microbiology encompasses numerous sub-disciplines including virology, mycology, parasitology, and bacteriology. The microbiologist separates these mixed populations into indi...
Read more

Experiment 6: Preparation of bacterial smear, Experiment 7: Simple staining and Experiment 8: Negative staining

-
Image
      Assalamualaikum and every good evening to everyone that read my post... The experiment I did in this week which is sixth week of basic technique of microbiology have three experiment. First is preparation of bacterial smears, next is simple staining and the last one is negative staining. Bacterial smears must be prepared prior to the execution of any of the staining technique. Bacterial cells are usually colorless because cytoplasm, for the most part, is transparent. Since the bacteria are colorless, it is almost essential to add a stain to make the bacteria more visible. Once stained, cell morphology can be observed. In simple staining, the bacterial smear is stained with a single reagent, which produces a distinctive contrast between the organism and its background. In negative staining requires the use of an acidic stain such as India ink or nigrosin. The acidic stain, with its negatively charged chromogen, will not penetrate the cells because of the negative cha...
Read more