Gram positive or negative

What was your unknown in the gram staining lab? How did you determine your unknown?

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2 years ago
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our unknown bacteria was Serratia Marcescens. It is a gram negative bacteria because in the end of the experiment, the stain was pink. Pink stain can be compared to the other gram negative bacteria, S. Epi. This bacteria was also stained pink showing it is a gram negative bacteria. The other comparative bacteria used, was E.coli- a gram positive bacteria.

2 years ago
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We discovered our unknown bacteria to be Streptococcus pyogenes. We used the Gram Staining technique to determine if the organism was Gram negative or positive and the organism would dye pink or purple. The organism dyed purple, which means it was positive.

2 years ago
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Our bacteria was Streptococcus pyogenes and was gram positive. The gram staining technique is used to be able to identify if the microorganism if it is gram positive it will be purple and gram negative which will be pink/red. By doing this you are able to identify if the microorganisms shapes and, size, and how it is grouped together.

2 years ago
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Our unknown was Serratia marcenses a round shaped bacteria. It was gram negative because it stained pink after the gram staining procedure.
Gram staining is a way to classify and recognise bacteria, other ways can be shapes, how they get together and sizes.
To do the gram staining procedure you need a primary stain that is usually crystal violet and stains purple, then you need a mordant, usually gram's iodine that is able to fix the primary stain only on the gram positive bacteria, so that when you get at the third step and you apply the decolorizer (acetone alcohol) the primary stain is removed just from the gram negative bacteria; the last step is to apply a counter stain (safranin) so that gram positive and negative bacteria can be easily compared

2 years ago
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Our unknown was Steptococcus pyogenes. The bacteria was gram positive because the stain came out as purple after we did the Gram Stain Lab. We used the Gram Staining procedure by staining the fixed bacteria of Crystal violet (rinse after 1 min.), then the Gram's Iodine (rinse after 1 min.), then we used a decolorizer ; Acetone Alcohol (rinse after 10-15 sec.), lastly we applied Safranin (rinse after 1 min.). After lightly blotting the wet slide (until dry) we put the slide under a microscope to compare the unknown to the gram negative and positive.

2 years ago
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Our unknown was Serratia Marcescens. The bacteria was gram negative because the stain came out pink after the Gram Stain Lab. We used an antiseptic technique and heat fixed the bacteria to begin the staining process. We then used Crystal violet and let it sit for one minute before rinsing it off, then we applied Gram's Iodine for one minute then rinsed it off. Then we applied the decolorizer Acetone Alcohol for 10-15 secs then rinsed it off, Finally we applied Safranin for one minute. We then looked under the microscope we saw it was pink and round. We determined that it was gram negative coccus. This method of gram staining then looking under a microscope is a common way of finding out microorganisms identification.

2 years ago
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Our unknown was Serratia Marcescens. The bacteria ended out turning pink when the lab was over showing us it was gram negative.To preform the expermeint we had to use acpectic technique. Then after we gram stained it, with crystal violet, gram's iodine,acetone alchol,then finally safranin. After doing all the following the next time we visited class it was obvious what our unknown was just by the color.

2 years ago
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the unknown was serratia mercenes (gram negative) the contrtol was e. coli (gram negative) and the gram positive bacterium was streptococcus pyogenis. the gram staining process starts off with a bacterial smear of 3 different bacteria. then you apply crystal violet for 1 minute, rinse, add grams iodine 1 minute, rinse, apply acetone for no more than 15 seconds, rinse, then add safranin for 1 minute to add pinki to gram negative microorganisms.

2 years ago
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The unknown was serratia mercenes, gram negative. Ecoli was our control, it turns out to be gram positive, and it looks like streptoccus. The gram staining technique helped us to discover the different types of microorganisms.(colors, shapes)

2 years ago
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Serratia mercenes was our unknown because it was pink and therefore gram negative. The staining process entailed, first preparing the slide, each specimen in individual circles. After applying organisms, we heat fixed the slides. After waiting for that to cool, we began staining it. First with crystal violet (with a minute wait), gram iodine (with another minute wait), alcohol (15 second wait), and safrinin (1 minute wait), rinsing between each application. This whole process leads to being able to see the organisms under a microscope, and be able to determine if they are positive (purple) or negative (pink). This technique was chosen over other techniques for those two reasons