Staining Techniques Flashcards
staining of these is very difficult because they hardly absorb, reflect ,refract or diffract much light
microorganisms
uses one dye and can be positive or negative staining
simple staining
uses basic dyes
positive simple staining
-uses acidic dyes
negative staining
– uses two or more dyes that will distinguish bacteria from each other because their cell walls have different reactions on dyes
differential staining
technique to add stain to specimens to make it more visible under the microscope
staining technique
– are of little use unless the specimens for viewing are prepared properly
microscope
important tool that aids in the observation of microorganism
microscopy
- is a culture-free method to identify and compare bacterial diversity from complex microbiomes or environments that are difficult to study
16s rRNA sequencing
– have the same refractive index as water
microorganism
When observed under a microscope, they are transparent or nearly invisible to the naked eye
microorganism
Must be fixed and stained to increase visibility, accentuate specific morphological features, and preserve for future use
microorganism
substance that adheres to a cell, giving the cell color
stain
Presence of color gives the cells significant contrast so are much more visible
stain
They are used to differentiate different types of organisms or to view specific parts of organisms
stain
spherical bacteria
cocci
rod shaped bacteria
bacilli
helical, twisted, spirochete shaped bacteria
spirilla/spirillus
comma shaped bacteria
vibrio
view different bacteria shapes
+1
- Bacterial arrangement (4)
clusters
chains
pairs (diploids)
no special arrangement
view different arrangement of cocci
+1
arranged in pairs or chains
strep
clusters, pairs and occasionally in short chains.
staphylococci
involves directly staining the bacterial cell with a positively charged dye in order to see bacterial detail, in contrast to negative staining where the bacteria remain unstained against a dark backround
simple staining
positive dye is used to adhere to a negatively charged plasma membrane (ex. Crystal violet, methylene blue)
positive staining