Class Notes (943,974)
US (364,907)
UF (4,168)
MCB (41)
MCB 3020 (13)
Lecture 4

MCB 3020 Lecture 4: Microbiology lecture 4

3 Pages
17 Views

Department
Microbiology and Cell Science
Course Code
MCB 3020
Professor
Abdolkarim Asghari

This preview shows page 1. Sign up to view the full 3 pages of the document.
8/31/2017
Microbiology Lecture FourExam 1
Basic dyes (positive) stick to surface of cells
Simple stain uses one stain to show morphology, size and arrangement
Types of dyes that may be used:
o Positive staining: uses basic dye that binds to the specimen, CV
o Negative Staining: uses acidic dye that binds to background, India ink
Examples of differential staining procedures:
o Gram stain (most common)
o Acid-fast stain (ex: for mycobacteria, Because need harsher stain)
o Structural stains (ex: capsule, flagella, spores)
If kept gram color, then gram positive. If lost original color, gram negative. Purple/blue=
positive, Pink= negative
Simple stainseverything same color, Crystal violet, methylene blue
Differential stainsacid fast, gram, endospore stain, India ink, Flagellar
Most important feature of stain (acid fast), is testing of TB
Gram stain shapes:
o Rods (bacillus), coccus (circle), vibrio (shape of smile), coccobacillus (kinda square),
spirochete (spiral shaped), Spirillum (wavy)
Bacillus and clostridium= has gram positive stain
Clostridium causes gangrene, anthrax
Fluorescence Microscopy:
Used as a diagnosis of dangerous diseases
o Dark-field microscopycolors background and sees shadow of organism
o Phase Contrast Microscopyuses density of different components of cell. With different
density, bends light differently
Atiody= protei that’s produed after fidig a ifetio
Fluorescent dye binds to antibody; used as diagnostic tool
Electron microscopy does’t use light soure ut uses eletro ea as light soure:
o TEM details of inside cell. Uses sharp tip to cut through cell
o SEMsurface details
Confocal scanning laser microscopy:
o Uses computer integration of images from many different focal planes (angles) to
generate 3-D pictures. VERY SHARP IMAGES!
o (REMEMBER) Fluorescent dye attached to antibodies are used in conjunction with laser
light source to produce sharp images
Characterization of light and electron microscopy
o Magnification
o Resolution
find more resources at oneclass.com
find more resources at oneclass.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
8/31/2017 Microbiology Lecture Four—Exam 1 • Basic dyes (positive) stick to surface of cells • Simple stain uses one stain to show morphology, size and arrangement • Types of dyes that may be used: o Positive staining: uses basic dye that binds to the specimen, CV o Negative Staining: uses acidic dye that binds to background, India ink • Examples of differential staining procedures: o Gram stain (most common) o Acid-fast stain (ex: for mycobacteria, Because need harsher stain) o Structural stains (ex: capsule, flagella, spores) • If kept gram color, then gram positive. If lost original color, gram negative. Purple/blue= positive, Pink= negative • Simple stains—everything same color, Crystal violet, methylene blue • Differential stains—acid fast, gram, endospore stain, India ink, Flagellar • Most important feature of stain (acid fast), is testing of TB • Gram stain shapes: o Rods (bacillus), coccus (circle), vibrio (shape of smile), coccobacillus (kinda square), spirochete (spiral shaped), Spirillum (wavy) • Bacillus and clostridium= has gram positive stain • Clostridium causes gangrene, anthrax Fluorescence Microscopy: • Used as a diagnosis of dangerous diseases o Dark-field microscopy—colors background and sees shadow of organism o Phase Contrast Microscopy—uses density of different components of cell. With different density, bends light differently • Antibody= protein that’s produced after finding an infection • Fluorescent dye binds to antibody; used as diagnostic tool • Electron microscopy (doesn’t use light source but uses electron beam as light source): o TEM— details of inside cell. Uses sharp tip to cut through cell o SEM—surface details • Confocal scanning laser microscopy: o Uses computer integration of images from many different focal planes (angles) to generate 3-D pictures. VERY SHARP IMAGES! o (REMEMBER) Fluorescent dye attached to antibodies are used in conjunction with laser light source to produce sharp images • Characterization of light and electron microscopy o Magnification o Resolution o Illumination source • Need electron microscopy to see viruses • Lower wave length= higher resolution (what clarity is) Recap • Simple stains—employs basic dye to impart a color to a cell. Easy way to increase the contrast between otherwise colorless cells and a transparent background • Differential stains—distinguishes one group of microorganisms from another • Gram stain—used to separate bacteria into two major groups, Gram-positive and Gram- negative. The staining characteristics of these groups reflect a fundamental difference in chemical structure of their cell walls. This by far most widely used staining procedure • Acid-fast stain—used to detect members of genus Mycobacterium in a specimen. Due to the lipid composition of their cell walls, these organisms do not readily take up stains • Special stains—stains specific structures inside or outside cell: o Capsule stain—because viscous capsule does not readily take up stains, it stands out against a stained background. This is an example of a negative skin stain o Endospore stain—S
More Less
Unlock Document


Only page 1 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit