Experiment 1Experiment 1
Gram stainGram stain
Yuyan Wang
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Guidelines and tips
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community
Ask the community for help and clear up your study doubts
University Rankings
Discover the best universities in your country according to Docsity users
Free resources
Our save-the-student-ebooks!
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
Gram Stain Technique in Medical Microbiology: Experiment 1 by Wang Yuyan, Lab Reports of Microbiology
Details about the Gram stain experiment in medical microbiology conducted by Wang Yuyan. various aspects of the technique, including the materials used, methods for staining bacteria, and the identification and diagnosis of different bacterial strains based on their staining properties. The experiment involves staining various bacterial strains such as Escherichia coli, Staphylococcus, and Neisseria meningitidis using different stains like crystal violet, Gram's iodine, and safranin.
What you will learn
- What safety measures should be taken while performing the Gram stain technique in a medical microbiology lab?
- Which bacterial strains are typically identified as Gram-positive and why?
- How does the Gram stain technique help in the identification and diagnosis of different bacterial strains?
- What is the role of crystal violet and Gram's iodine in the Gram stain technique?
- What are the two main groups of bacteria identified by the Gram stain technique?
Typology: Lab Reports
2020/2021
1 / 27
This page cannot be seen from the preview
Don't miss anything!
Related documents
Partial preview of the text
Download Gram Stain Technique in Medical Microbiology: Experiment 1 by Wang Yuyan and more Lab Reports Microbiology in PDF only on Docsity!
Experiment 1Experiment 1
GramGram stainstain
Yuyan Wang
Bacterial stain
Living bacteria stain
Killed bacteria stain
Positive staining (^) Negative staining
Common stain
Single-dye stain
Special stain
Complex stain Endospore stain^ Capsule stain
Gram stain
Cell wall stain
Acid fast stain
Methods for staining bacteriaMethods for staining bacteria
Streptococcus (Gram stain, oil 100 )
100 )
StaphylococcusStaphylococcus (Gram stain, oil 100 )
100 )
Capsule of pneumococcuspneumococcus capsule stain, oil 100 )
100 )
Spore of spore stain, oil 100 )
100 )
Clostridium tetani
®
®
®
®
® ® ® ®
Thick peptidoglycan 90% peptidoglycan Teichoic acids Not many polysaccharides
Gram stain
Divides bacteria into 2 groupsDivides bacteria into 2 groups
GramGram--positivepositive GramGram--negativenegative
Thin peptidoglycan 5-10% peptidoglycan No teichoic acids Outer membrane has lipids, polysaccharides
applicationapplication
Identification:
Color, shape, arrangement, endospore
Diagnosis
toxin, endotoxin
Treatment
antibiotic selection: G+, G-
MaterialsMaterials
l
l
l
4 students sharing
2 students sharing
Everyone:
® ® ® ® ® ® ® ® ® ® ® ® Cleaning paper for lens (the blue box) 1 bottle of immersion oil (cedar oil and aether (cleaning solution) 1 bottle of saline Drying paper Marker
Bacteria Strains: and (cultures on slants). Gram stain kit: Bunsen burner Dipper
Microscope slides: 1- Inoculating loops: Microscope (in the storages under the bench)
Staphylococcus albus Escherichia coli
Gram stainGram stain
® Procedure
1. Prepare bacterial smears
2. Gram stain
3. Observation by microscope
CAUTION!
Pick up a very small amount of the organisms
Pick up organisms from a tube slant
Be sure to cool the loop completely before inserting it into a medium. A loop that is too hot will spatter the medium and move bacteria into the air.
Making bacterial smears
Be sure to flame the inoculating loop before returned it to rack.
Gram stainGram stain
- Cover the smear with for
- Briefly wash off the stain. Drain off excess water.
- Cover the smear with solution for 10 seconds.
- Pour off the Gram s iodine and washed by water.
5 Flood the smear with
Thick smears will require more time than thin ones.
- Stop action of the alcohol by rinsing the slide with water for a
- Cover the smear with
- Wash gently for a few seconds, blot dry with bibulous paper, and air-dry.
- Examine the slide under oil immersion.
crystal violet 10 seconds.
Gram s iodine
95% ethyl alcohol for This step is critical.
safranin for
10 to 20 seconds.
Decolorization has occurred when the solvent flows colorlessly from the slide.
10 seconds.
few seconds.
10 10 seconds
10