In 1884, Hans Christian Gram, a Danish bacteriologist,
tried to find a strattera online universal stain that will work with all the bacteria. In the process >> <<, he discovered that the bacteria can be divided into two groups
who saved a spot called "gram-positive," and one that did not, under the
-- called "gram negative". His unique method of identifying these two groups
is the first step in any process of bacterial identification. Even a simple definition >> << that bacteria or gram-negative gram-positive sample may be directly
doctor in the diagnosis, since different bacteria cause different diseases. For example, the bacteria that cause scarlet fever is a gram-positive, while >> << that causes typhoid fever, cholera, or gram-negative. Gram staining helps doctors make a diagnosis, but can >> << it will also help provide treatment? What is the relationship between grams
classification and use of antibiotics? As usual antibiotics interact differently
Gram-positive and Gram-negative bacteria? Answer these questions
through experimentation. Q: There are four common antibiotics (penicillin, ampicillin
neomycin and erythromycin) have the same effect as
, Gram-negative and gram-positive bacteria? Observe / Data Collection: Do some research to find information about
antibiotics and Gram staining, so that you can do
reasonable hypothesis. Hypothesis: Based on your research, write more >> << hypotheses predict the answer to this question. Experiment: an experiment to test the hypothesis
need two parts. In the first part, to perform gram stain for bacteria cultures to determine which are Gram
and that gram-positive. The second part of a controlled experiment
measure the influence of each antibiotic for each type of bacteria. Working with chemicals and bacteria can be dangerous. Before you begin
read it. Part One - Gram material live bacteria cultures - and. (You can also crop, and
(
contains crystal violet stain, gram stain of iodine, ethyl alcohol solvent, safranin O
contrasting color, a simple microscope slides, pipettes, cover)
Procedure Some steps are difficult to carry out the process of Gram fine. To practice, it's a good idea to "control" slide.
Try to collect some of the bacteria between the teeth (using a toothpick) and
placing it on a glass slide with a drop of water . If the Gram staining procedure
done correctly, the slide should have a mixture of gram-negative and gram
-positive cells as well. some neutrophils (white blood cells) with pink cores >> << After you've tried, that the spots of each of live bacteria cultures
using the following procedure:
Sterilize your needle vaccinations, putting it in a candle flame.
Let cool for 3 - 5 seconds.
Make a smear of the sample by placing a small amount of bacteria from one of the cultures >> << a clean glass slide with a needle inoculation. Take another slide and
use the edges to clean up or "smear" the specimen in a very thin film of material >>.
<< Let the sample on the slide air dry, then heat fix by passing slide >> << a candle flame three -4 times. (slide should not become too hot to touch, and
never have to stop as it passes through the flame).
Cover the sample with 1-2 drops of crystal violet stain on 60 seconds
, and then gently rinse off very slow flowing water from the tap or more
delicate bubbles from washing. bottle (if the water is running too fast and hits
slide too much effort, the sample will be washed off) .
Cover the sample with a few drops of iodine in the Gram for 60 seconds, then gently rinse the sample again, as in step
4. use of ethanol as a solvent. This is the most sensitive step, because if
ethanol remained in the sample is too long, it will brighten
Gram-positive cells, as well as Gram-negative. Tilt slide gently
apply a drop of alcohol on the slide above the sample, so that the alcohol drains
throughout the sample. stop using alcohol, the liquid flows
from the edge of the slide is not a color.
small part of the smear should be colorless. It takes about 5 seconds. Wash the slide gently again. Note that the Gram-positive cells retain some of the violet color, but most >> << stains will wash off the solvent.
Cover the sample with a few drops of safranin stain, as a counter stain
for 60 seconds and then gently rinsed one more time. Blot
slide with filter paper (paper towel will work if you do not have anything else
), but do not rub swab sample. Put the cover on the smear. Now you are ready to consider a slide under a microscope at each increasing the level >>.
<< How do so, look at the cells purple. This gram-positive cells
, who retained crystal violet stain. cells are pink or red color are Gram
cells. In these cells, crystal violet was washed off
on ethanol and safranin replace .. Once you have determined which of your living cultures of gram-negative and
which is gram-positive, clearly identify them and move on to the next part of the experiment
Part Two - Antibiotic One way to check the bacteria sensitivity to antibiotics is to use the
Kirby-Bauer or "Disk diffusion" method. This method consists in measuring the
suppression of bacterial growth around the antibiotic disc placed in the
culture. two sterile materials (penicillin, ampicillin,
Neomycin and erythromycin)
Procedure Preparation of agar in accordance with the directions on the label, then pour 10-15 ml
in each Petri dish (enough to cover bottom of dish.) >> << Let the dish stand (covered) for about an hour until the agar is firm. Sterilize your needle inoculation, and then instill one dish with a >> < <Gram-positive bacteria. slightly zig-zag needle over the surface of agar >> <<, rotate the dish, and do it again. Do this several times to get the maximum spread of
. Place one disc each type of antibiotic different locations on the agar >> << (used sterile forceps). Press down lightly drive
attach it to the agar. Cover the dish when you're done. Repeat steps 2-3 with Gram-negative bacteria. Study each dish after 24 hours. If bacteria culture grows
until the edge of the disk antibiotic, it is not amenable to that antibiotic.
If there is a circular zone around the disk, where
slows the growth of bacteria, measure and record diameter of the circle. Note the effect of each antibiotic disk in each petri dish.
You can also shoot. Repeat step 5, after 48 hours. When you have finished your observations of bacterial cultures, put a tablespoon of >> << ; household bleach in a bowl, cover them, seal them in a plastic bag and throw
them. Data Analysis / Data Analysis Summary form. How does one carry antibiotic bacteria in each culture >> <<? Were there more the total effective antibiotics against gram-positive or
Gram-negative bacteria? What are the limitations of your research? Can you get more accurate results if you have experienced a greater number of bacteria culture
? form of detention. Do your results support your hypothesis,
Why or why not? What the results tell you about the process
antibiotics, how you could extend this study to learn more
about the relationship of bacteria and antibiotics? Security Notice chemicals are often used to prepare slides >> << can be toxic, corrosive and other related hazards.
Always carefully read entire label before using chemicals. Make sure you understand the dangers
, the right equipment to ensure Security to be, and what do you do
in the event of a spill or contact with skin. Spots for gram stain process
will discolor clothes and skin. Key that you should be >> << include safety goggles (splash type), chemically resistant gloves, chemical resistant lab apron. work in a clean, well-ventilated, uncluttered
, where you can quickly wipe away spills. Always keep chemical bottle tightly closed. Do not use antibiotic discs, if you are allergic to those forms of antibiotics.
bacteria, you can work with
be dangerous. Always wash your hands thoroughly before and after treatment
cultures of bacteria. Washing them before to minimize pollution >> << crops you grow bacteria. washing them and then will be to minimize the impact
harmful bacteria that can grow in your culture. When you have completed the study of culture
enough to pour household bleach in it to cover the bottom
dish. Then cover the culture, seal it in a plastic bag and throw it away.
,
