+ 1-888-787-5890  
   + 1-213-471-2244  

Essay/Term paper: Bacteria classification by gram staining

Essay, term paper, research paper:  Biology

Free essays available online are good but they will not follow the guidelines of your particular writing assignment. If you need a custom term paper on Biology: Bacteria Classification By Gram Staining, you can hire a professional writer here to write you a high quality authentic essay. While free essays can be traced by Turnitin (plagiarism detection program), our custom written essays will pass any plagiarism test. Our writing service will save you time and grade.

Bacteria Classification By Gram Staining

Presented By : Karim A. Zaklama 92-1509 Sci. 453-01


To test a sample of laboratory prepared bacteria and categorise it
according to Christian"s gram positive and gram negative classes and also by
viewing it under a high powered microscope and oil immersions; classify its
shape and note any special characteristics.


Bacteria was categorised into two groups in 1884 by the Danish
Bacteriologist Christian, gram positive and gram negative by a staining
technique where the ability to avoid de-coloration of Crystal Violet solution
by alcohol would render the category of gram positive, and gram negative if the
bacteria is de-coloured. This could be noted by the final colour of the
bacteria: a violet colour where Gram positive and a pink colour of the Safranin
added pending the de-colouring process.


1. Bacteria Sample 2. Microscope Slide 3. Gram Staining Kit and Wash Bottles
a. Crystal Violet Solution b. Iodine Solution c. 95% Ethyl Alcohol d.
Safranin e. Distilled Water 4. Bibulous Blotting Paper 5. Microscope 6. Oil


A. Preparation :

1. Bacteria is cultivated on agar jelly in an incubator at 25°C for 24 hours. 2.
Obtain a microscope slide and with a toothpick, smear a thin coat of the
bacteria sample onto the slide 3. Cover the smear with a drop Crystal Violet
and leave standing for 20 seconds 4. Wash off the stain with distilled water;
drain and blot off the excess with bibulous paper. 5. Apply Gram"s Iodine on
the smear and leave to stand for 1 minute. 6. Drain the excess iodine and apply
95% Ethyl alcohol for 20 second duration or till the alcohol runs clearly from
the slide. 7. The smear should rinsed for a few seconds with distilled water to
stop the action of the alcohol. 8. Drain and blot off the excess with bibulous
9. Introduce Safranin to the smear and leave standing for 20 seconds. 10. Wash
off the stain with distilled water; drain and blot off the excess with bibulous
paper. 11. Leave the slide to air dry.

B. Examination:

1. Place the slide under microscope on low powered lens. 2. Move the slide
using the apparatus until the sample can be seen as a blur under the microscope.
3. Focus the lens to ensure that there is a sample directly under the lens. 4.
Move to higher powered lens, repeat step 3. 5. Move to higher powered lens,
repeat step 3 6. Move microscope aside and add Oil immersion, leave for a few
seconds and re-examine the slide.

Note Shape and colour and any other observations.

Results and Observations:

It was evident by visual examination that the alcohol was de-colouring or a
least partially de-colouring the bacteria.
The sample appeared a dark pink or close to violet by the naked eye; a
microscope was needed to ensure results.
Under the low powered microscope shades of pink were noted.
Under the medium power, the shades were more clear but no shape could be made
Under the high powered microscope clumps of pink rod (bacilli) shaped bacteria
cells could be observed.
Under Oil Immersion and high powered lens the cells could seen more spaced out
and thus a clearer indication of the pink colour, bacilli shape and spores could
be made out in the individual cells.


The Shape was noted as Bacilli (Rod-like) shaped cells; a gram variable
shape, distinct in either Gram Negative or Gram positive bacteria.
The final colour of the cells were stained pink by the Safranin showing
the de-coloration of the crystal violet proving the bacteria is of the gram
negative class.
Under oil immersion the cells became more sparse and under the high
powered lens of the microscope spores could be seen, as little bubbles, in the
cells. This tells us that the bacteria was in its terminal state.
The presence of spores in the bacteria at its terminal state tells us
that the bacteria could be an old culture. Old bacteria cultures which are gram
positive tend to de-colour, yet more slowly than gram negative bacteria. The
speed of de-coloration was not inspected very clearly thus no further conclusion
could be reached, yet it is possible that this an old culture of Bacilli shaped
Gram Positive bacteria.


It is recommended that the same sample be tested again for de-
coloration; focusing on de-coloration speed. If the de-coloration is fast then
the sample is definitely gram negative, slow de-coloration would tell us it is
gram positive. For future samples it would be recommended to keep the bacteria
sample for this specific test for only 16 hours as recommended to avoid the
presence of old cultures which are anomalous to this test.


Other sample model essays:

Euclidean Geometry Geometry was thoroughly organized in about 300 BC, when the Greek mathematician Euclid gathered what was known at the time, added original work of his own, and arranged ...
Fibonacci Numbers The Fibonacci numbers were first discovered by a man named Leonardo Pisano. He was known by his nickname, Fibonacci. The Fibonacci sequence is a sequence in which e...
Fractal Geometry "Fractal Geometry is not just a chapter of mathematics, but one that helps Everyman to see the same old world differently". - Benoit Mandelbrot The world of mathematics u...
Frank Lloyd Wright Frank Lloyd Wright was a courageos man in the sense that he was not afraid to accept critisism from people and fellow architects. Throught his careerhe has faced many ty...
Carl Friedrich Gauss Kevin Jean-Charles August 10, 1996 Seq. Math Course 2 Period 1&2 This report is on Carl Friedrich Gauss. Gauss was a German scientist and ma...
Science / Gauss
Gauss Gauss was a German scientist and mathematician. People call him the founder of modern mathematics. He also worked in astronomy and physics. His work in astronomy and physics is near...
Science / Georg Cantor
Georg Cantor I. Georg Cantor Georg Cantor founded set theory and introduced the concept of infinite numbers with his discovery of cardinal numbers. He also advanced the study of trigonom...
Gods Gift to Calculators: The Taylor Series It is incredible how far calculators have come since my parents were in college, which was when the square root key came out. Calculators since ...
Science / Leonhard Euler
Leonhard Euler Leonhard Euler, (born April 15, 1707, died Sept. 18, 1783), was the most prolific mathematician in history. His 866 books and articles represent about one third of the entir...
Science / Leonhard Euler
Leonhard Euler Euler, Leonhard (1707-83), Swiss mathematician, whose major work was done in the field of pure mathematics, a field that he helped to found. Euler was born in Basel and studi...
it is always perfect
Frederick, Maryland, United States
The experience with Dream Essay is stress free. Service is excellent and forms various forms of communication all help with customer service. Dream Essay is customer oriented. Writer 17663 is absolutely excellent. This writer provides the highest quality of work possible.
Browns Mills, New Jersey, United States
Dream Essay is excellent. Writer 7135 is excellent. Met all requirements of the paper produce superb work. Thank you for your time and an excellent paper.
Browns Mills, New Jersey, United States
Writer 37301 is excellent produces assignments ahead of deadline which provides enough time for review and revisions, and the assignments are done according to rubrics. Excellent
Browns Mills, New Jersey, United States
Only competent & proven writers
Original writing — no plagiarism
Our papers are never resold or reused, period
Satisfaction guarantee — free unlimited revisions
Client-friendly money back guarantee
Total confidentiality & privacy
Guaranteed deadlines
Live Chat & 24/7 customer support
All academic and professional subjects
All difficulty levels
12pt Times New Roman font, double spaced, 1 inch margins
The fastest turnaround in the industry
Fully documented research — free bibliography guaranteed
Fax (additional info): 866-332-0244
Fax (additional info): 866-308-7123
Live Chat Support
Need order related assistance?—Click here to submit a inquiry
© Dreamessays.com. All Rights Reserved.
Dreamessays.com is the property of MEDIATECH LTD