Chapter 2 Flashcards
Hooke coined the term ____ for the individual units he observed
Cell
If the sample is to be stained, a _____ must be made.
Smear
The most simplest type of preparation is the _____, in which the specimen is placed on the slide in a drop of liquid.
Wet mount
The fixing of a sample refers to the process of attaching cells to a slide.
Fixation
Positively charged
Negatively charged
Basic dyes
Acidic dyes
A_______ maybe used to hold the stain or coat the specimen to enlarge it
Mordant
Microbe is colored against a light background
Microbe is transparent against a colored background
Positive stain
Negative stain
A single dye is used to emphasize particular structures in the specimen. Generally makes all of the organisms in a sample appear to be the same color, even if the sample contains more than one type of organism
Simple staining
Use a combination of dyes to highlight differences between microbes
Differential staining
Most common differential stain
Classifies bacteria into gram positive 🟪 and gram negative 🟥 based on differences in cell wall composition
Gram staining
Has a thick peptidoglycan
Has a thin peptidoglycan
Gram positive thick
Gram negative thin
Gram Staining
Primary staining =
Mordant =
Decolorizer =
Counter stain =
Crystal violet 1st stain 🟪
Iodine 🟥
Alcohol
Safranin 🟥
ACID FAST STAINING
Primary stain ______
Stain penetrates waxy coating of acid fast cells
Carbolfushin
Pink acid fast 💓
Acid fast staining
ACID FAST
Counterstain
Stains non acid fast cells
Methylene blue
Blue non fast acid cells
Acid fast cells
ENDOSPORE STAINING
Primary stain =
Decolorizer with water
Counter stain
Malachite green 🟢
Safranin 🔴
Green endospore and red vegetative cells
Endospore staining
An image of the surface of the specimen is created
The specimen is coated with metal (gold)
Electrons are deflected when they hit the specimen
Scanning electron microscopy
In _____ electrons pass through the sample
Is useful for visualizing the internal structures of cells and viruses
Staphylococcus aureus Ebola virus
Transmission electron microscopy tem
Uses antibodies linked to fluorescent molecule
This is helpful for detecting specific microbes or cellular structures
Gonorrhoeae can be viewed on this microscope
Immunofluorescence microscopy
Uses a light stop above the condenser
This results in a light cells on dark background
Treponema palladium (syphillis) can be viewed on this microscope
Darkfield microscopy
Is the most commonly used microscope
Images appear on a light background
The objective lens sits above the specimen and comes in a variety of powers
Typical powers 4X, 10x, 40x, and 100x
This allows to see objects as small as bacteria, but not smaller objects such as viruses
Bright field microscope
The item being viewed is called a _____ and is placed on a glass slide which then clipped into place on the ____
Specimen
Stage
These knobs move the slide on the surface of the stage but do not raise or lower it
XY mechanical knobs
The _____ is used for large scale movements with 4X and 10x objective lens
The _____ is used for small scale movements especially 40x or 100x objective lens
Coarse focusing knobs
Fine focusing Knobs
Images require intense lighting
Illuminator
Focuses all of the light rays on the specimen to maximize illumination. The position of the condenser can be optimized using the attached _____, once the optimal distance is established.
Condenser
Condenser focus knob
If less than maximal light levels are needed, the amount of light striking the specimen can be easily adjusted by opening or closing a _______ between the condenser and specimen
Diaphragm
In some cases, brightness can also be adjusted using the _______, a dimmer switch that controls the intensity of the illuminator
Rheostat
