IBG 102 lab report: March 2012

Tuesday, 20 March 2012

Lab 1 Report written by Teoh Leong Sin

Name: TEOH LEONG SIN
Matrix no: 111433
Lab 1: Principle and use of microscope

1.1 Setting up and using microscope

Introduction:
In order to be seen, microorganisms need to be magnified. Despite advances in other area of microscopy (for example, the electron microscopy), the light microscopy is still the instrument most frequently used for viewing microorganisms.

Objective:
Learn to use a simple bright-field microscope correctly.

Results:
Total magnification = objective lens power x eyepiece lens power(10x)

Salmonella enteritidis under 40x magnification:

Salmonella enteritidis under 100x magification:

Salmonella enteritidis under 400x magnification

Discussions:

1) Specimen is observed from lowest magnification to highest magnification (x40,x100,x400)

2) Light intensity is adjusted to observe the specimen clearly.

3)Specimen focused by adjusting fine and coarse adjustment knob to obtain a view of specimen.

4)Colony marphology of salmonella enteritidis:

a)Shape:circular

b)Size: tiny (punctiform)

c) Surface: shiny and smooth in appearence

d)Color: Red

Conclusion:

I could get a clearer image of Salmonella enteritidis in the magnification of x400. This mean the higher the magnification of objective lens, the clearer the view of image.

References:

http://en.wikipedia.org/wiki/Salmonella

http://quizlet.com/370451/microbiology-student-presentations-flash-cards/

1.2 Examination of cells

Because of their extreme minuteness, bacteria are not generally studied with the low-power or high power-power dry objectives. Instead they are stained and observed with the oil immersion objective.

The wet mount methods enables you to study the sizes and shapes of living microorganisms (drying or staining microorganism distort them). It also enables you to determine if cells are motile. The wet mount method is quick and easy, and does not require special equipment.

Objective:

-To provide an experience in the use of microscope

- To illustrate the diversity of cells and microorganisms.

Results:

Saccharomyces cerivisiae (yeasts) under x1000 magnification:

Lactobacillus fermentum under x1000 magnification:

Discussion:

1)The oil immersion fills the space between the objective lens and specimen and matches the refractive index of the glass coverslip and glass objectives lens. At a given focal length, this allow me to achieve a greater numerical aperture.

2)There are 2 different types of microorganisms which been observed:

a)Lactobacillus fermentum

b)Saccharomyces cerivisiae

3)Colony marphology of Lactobacillus fermentum

-Shape:Rod

-Size:Tiny

-Surface:Smooth

-Texture:moist

-Color:Violet

4)Colony marphology of Saccharomyces cerivisiae

-Shape:Circular

-Size:Tiny

-Surface:Smooth

-Texture:Moist

-Color:Lemon yellow

Conclusion:

Oil immersion with 1000x magnification lens allow us to observe the specimen more detail which include shape,size,surface,texture and color.

References:

http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae

http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2958.2003.03332.x/full

http://microbewiki.kenyon.edu/index.php/Lactobacillus

http://en.wikipedia.org/wiki/Lactobacillus_fermentum

Lab 1 Report written by Tan Hwee Feng

Name : TAN HWEE FENG
Matric No : 111427

1.1 Setting up and using the microscope

Introduction

In order to be seen, microorganisms need to be magnified. Despite advances in other area of microscopy (for example, the electron microscope), the light microscope is still the instrument most frequently used for viewing microorganisms.

Objective

Learn to use a simple bright-field microscope correctly.

Results

Total magnification = objective lens power x eyepiece lens power(10x)

Salmonella enteritidis under 40x magnification:

Salmonella enteritidis under 100x magnification:

Salmonella enteritidis under 400x magnification:

Discussions

1) Microscope is positioned so that it can be observed through the eyepiece comfortably.
2) We adjust the light intensity using the brightness control.
3) We adjust the mechanical stage being higher or lower by using coarse-focus and fine-focus
   knobs so that the objective lens is focused on the specimen.
4) We usually begin with low power (4x objective lens, 10x objective lens) to observe specimen
     roughly and with wider view. Then, we switch to high power (40x objective lens) to observe
     more detail and a clearer view of specimen.
5) Colony morphology of Salmonella enteritidis:
    Shape: circular
    Size: tiny (punctiform)
    Surface: shiny and smooth in appearance
    Color: red

Conclusion

The higher the magnification of objective lens, the clearer the view of specimen that we can be observed. The view is narrower and more specific for higher magnification.

References

http://quizlet.com/370451/microbiology-student-presentations-flash-cards/
http://en.wikipedia.org/wiki/Salmonella

1.2 Examination of cells

Introduction

Because of their extreme minuteness, bacteria are not generally studied with the low-power or high power-power dry objectives. Instead they are stained and observed with the oil immersion objective.
The wet mount methods enables you to study the sizes and shapes of living microorganisms (drying or staining microorganism distort them). It also enables you to determine if cells are motile. The wet mount method is quick and easy, and does not require special equipment.

Objectives

To provide an experience in the use of microscope.
To illustrate the diversity of cells and microorganisms.

Results

100x objective lens x 10x eyepiece lens = 1000x magnification (with immersion oil)

Saccharomyces cerivisiae (yeast) under 1000x magnification:

Lactobacillus fermentum under 1000x magnification:

Discussions

1) The 'oil immersion objective' meaning that a small drop of special immersion oil is placed on the
    slide and the front lens of the objective is dipped into it for viewing.
2) The oil immersion fills the space between the objective and the specimen and matches
     the refractive index of the glass cover slip and glass objective lens. At a given focal length, this
     allows us to achieve a greater numerical aperture (better light collection efficiency, better
   resolution).
3) Two different types of microorganisms are observed by using immersion oil:
- Saccharomyces cerivisiae (yeast)
- Lactobacillus fermentum
4) Colony morphology of Saccharomyces cerivisiae (yeast):
    Shape: circular
    Size: tiny
    Surface: smooth
Texture: moist
    Color: lemon yellow
5) Colony morphology of Lactobacillus fermentum:
Shape: rod
    Size: tiny(smaller than yeast)
    Surface: smooth
Texture: moist

    Color: violet

Conclusion

100x objective lens immersed in oil can get a clearer view of the specimen. Hence, 1000x magnification with 100x oil immersion objective lens has a good resolution and allow us to observe clearer image.

References

http://microbewiki.kenyon.edu/index.php/Saccharomyces
http://en.wikipedia.org/wiki/Lactobacillus_fermentum
wiki.answer.com/q/Why_is_oil_necessary_when_using_the_90x_to_100x_objective

Ibg 102 lab report 1 prepared by Tang Su Xian

Name : Tang Su Xian
Matric's card no.:111431
Lab 1: Principles and use of microscope

1.1 Setting up and using the microscope

Introduction

In order to be seen, microorganisms need to be magnified. Despite advances in other area of microscopy ( for example, the electron microscope ), the light microscope is still the instrument most frequently used for viewing microorganisms.

The function of any microscope is to enhance resolution. The microscope is used to create an enlarged view of an object such that we can observe details not otherwise possible with human eye. Because of the enlargement, resolution is often confused with magnification, which refers to the size of an image. In general, the greater the magnification, the greater the resolution , but this is not always true. There are several practical limitations of lens design which can result in increased magnification without increased resolution.

The total magnification of the image seen is calculated by the following formula:

Total Magnifications= Objective Lens Power × Eyepiece Lens Power

Objective

Learn to use a simple bright – field microscope correctly.

Results

Stained cells under magnification of (40 x, 100 x, 400 x).
1.) Salmonella enteritidis under 40x magnification

2.) Salmonella enteritidis under 100x magnification

3.) Salmonella enteritidis under 400x magnification

Discussions
1.)    The specimen was observed using the lowest magnification which is 40x to the 400x.

2.)    While observing the images, fine adjustment knob is used first followed by the coarse adjustment knob to ensure that the image is clear and focused at the centre.

3.)    Light intensity is adjusted to enable the correct amount of light enters the microscope and diaphragm is also adjusted to have a clearer view of the specimen.

4.)    The microorganism that was observed and drawn is Salmonella enteritidis.

5.)    The properties of the Salmonella enteritidis:

-Shape: Rod form

-Size: Tiny

-Surface: Shinny

-Texture: Smooth

-Color: Red

Conclusion

As a conclusion, I found that the magnification and resolution are equally important. I can greatly magnify an image, but unless the resolution is excellent I can see only fuzzy image. Likewise, I can obtain excellent resolution, but without magnification I can not see detail. Besides, I also found that I could get a clearer and larger of the image of Salmonella enteritidis as I observed using the 400x magnification.

References

http://en.wikipedia.org/wiki/Salmonella

http://textbookofbacteriology.net/salmonella.html

http://bioweb.uwlax.edu/bio203/s2009/meinhard_jaso/Adaptation_.htm

1.2 Examination of cells

Introduction

Because of their extreme minuteness, bacteria are not generally studied with the low-power or high power dry objectives. Instead they are stained and observed with the oil immersion objective.

Objective

-To provide an experience in the use of microscope.

-To illustrate the diversity of cells and microorganisms.

Results:

Lactobacillus fermentum (1000x magnification)

Yeast (Saccharomyces cerevisiae) (1000x magnification)

Discussions

1.) The oil immersion fills the space between the objective lens and specimen and matches the refractive index of the glass coverslip and glass objective lens. At a given focal length, this allows me to achieve a greater numerical aperture.

2.) The microorganisms that i observed in this experiment were Lactobacillus fermentum and Saccharomyces cerevisiae.

3.) The morphology of Lactobacillus fermentum :

-Shape: Rod

-Size: Tiny

-Surface: Smooth

-Texture: Moist

-Color: Violet

4.) The morphology of Saccharomyces cerevisiae :

-Shape: Circular

-Size: Tiny

-Surface: Smooth

-Texture: Moist

-Color: Lemon yellow

Conclusion

As a conclusion, i could get a clear view on the morphology of the microorganisms like Lactobacillus fermentum and Saccharomyces cerevisiae in this experiment by using immersion oil which could ensure magnification of 1000x achieved while still preserving good resolution.

References

http://en.wikipedia.org/wiki/Lactobacillus_fermentum

http://microbewiki.kenyon.edu/index.php/Lactobacillus

http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae

http://bioweb.uwlax.edu/bio203/s2007/nelson_andr/

wiki.answers.com/Q/why-is-oil-necessary-when-using-the-90x-to100x-objective

Lab Report 1 by Ooi Sin Ying

Name         : Ooi Sin Ying
No. matrice : 111410

1.1 Setting up and using the microscope

Introduction :
In order to be seen, microorganisms need to magnified. Despite advances in other area of microscopy (for example, the electron microscope), the light microscope is still the instrument most frequently used for viewing microorganisms.

Objective     :
Learn to use a simple bright-field microscope correctly.

Result          :

1. 4xobjective X 10xobjective = 40x magnification

2. 10x objective X 10x objective

3. 40x objective X 10x objective

Discussion ：

1.The light intensity is adjusted using the brightness control.

2.Specimen is observed from the lowest power objective, 4x magnification followed with 10x

magnification and 40x magnification.

3.The total magnification of the image is calculated by multiplying the objective lens power by the

eyepieces lens power.

4.Course-focus and fine-focus adjustment knobs are rotated to raise and lower the mechanical stage

so that the objective lens is focused on the specimen. Fine-focus knob is used to moves the stage

while looking through the microscope.

5.Morphology of the Salmonella enteritidis :

-Shape : circular

-Size : tiny and punctiform

-Surface : shining and smooth

-Colour : red

Conclusion :

Each parts of the microscope has their own function in giving the best view of specimen. The higher the magnification of the objective lens the clearer and larger view of specimen will be provided.

Reference :

-http://www.bristol.ac.uk/vetpath/cpl/critillum.html

-http://quizlet.com/370451/microbiology-student-presentations-flash-cards/

1.2 Examination of cells

Introduction :
Because of their extreme minuteness, bacteria are not generally studied with the low-power or high-power dry objectives. Instead they are stained and observed with the oil immersion objective.

The wet mount methods enables you to study the sizes and shapesof living microorganisms (drying or staining microorganism distort them). It also enables you to determine if cells are motile. The wet mount method is quick and easy, and does not require special equipment.

Objective :

-To provide an experience in the use of microscope.

-To illustrate the diversity of cells and microorganisms.

Result :

Under 100x objective X 10x eyepiece = 1000x magnification

1.Saccharomyces cerevisiae (Yeast)