What is a Peachtree dish?
What is a Peachtree dish?
A Petri dish (alternatively known as a Petri plate or cell-culture dish) is a shallow transparent lidded dish that biologists use to hold growth medium in which cells can be cultured, originally, cells of bacteria, fungi and small mosses.
What can I use instead of a petri dish?
For containers, you can use foil muffin tins, clear plastic cups covered with plastic baggies, clear Tupperware with lids, or real petri dishes. We’re going to use clear deli containers, so that we can recycle while we learn.
What is a petri dish and what is it used for?
To culture cells
Why is it called a petri dish?
The Petri dish is named after German bacteriologist Julius Richard Petri. Petri worked as a military physician for the German army and was assigned to a laboratory in Berlin’s Imperial Health Office in 1887.
What is the red stuff in a petri dish?
Agar is a gelatinous polymer substance derived from red algae and commonly used in a biological laboratory setting as a substrate. Agar plates are petri dishes containing agar in combination with a growth medium to culture microorganisms such as bacteria
Why are petri dishes inverted after they cool?
Inverting Petri plates after they cool reduces the risk of contamination by air-borne particles. When in the incubator growing cultures, Petri dishes are inverted because moisture condenses on the lid and will drop down onto the agar/growth medium causing moisture problems.
In which quadrant will we find the most bacteria?
first quadrant
How long does it take for bacteria to grow on agar?
4-6 days
How do you get rid of condensation on agar plates?
How do you get rid of condensation from petriplates regenerating rice calli? after pouring the agar plates, leave the lid slightly open in a sterile hood till the plates cool down. It may take about a hour to be safe. Then leave put the lids fully and leave it at room temperature overnight.
What would happen to plates poured with agar that is too hot?
if plates are poured with agar that is too hot, then the agar would kill the bacteria. Agar is the support medium for bacterial and fungal culture, as nutrients, antibiotics, salts and various growth enhancers. Too hot agar would kill the bacteria as the bacteria would get denatured
How can a streak plate become contaminated?
How can a streak plate become contaminated? If the loop is not sterilized. If you drop the plate. If lid isn’t on.
How do you identify bacteria on agar?
Colony morphology is a method that scientists use to describe the characteristics of an individual colony of bacteria growing on agar in a Petri dish. It can be used to help to identify them. A swab from a bin spread directly onto nutrient agar. Colonies differ in their shape, size, colour and texture.
What color is bad bacteria?
In the case of bacteria, the pigments are not just green (as in blue-green cyanobacteria) but can be orangish (as in marine cyanobacteria) or even purple (as in purple bacteria). When these pigments are damaged or when the organism dies, the pigments change color
What are two methods of identifying bacteria?
Among the techniques we use are:
- DNA sequencing – to identify bacteria, moulds and yeasts.
- Riboprinter analysis – for bacterial identification and characterisation.
- Repeat–based polymerase chain reaction – for assessing the similarity of microorganisms.
- Rapid pathogen confirmation by polymerase chain reaction.
How do you tell the difference between a bacterial colony and a fungal colony?
The main difference between bacterial and fungal colonies is that bacterial colonies are small, smooth or rough colonies with defined margins while fungal colonies are large colonies with a fuzzy appearance. Furthermore, bacterial colonies look wet and shiny while fungal colonies are powder-like
How do you identify bacteria?
When identifying bacteria in the laboratory, the following characteristics are used: Gram staining, shape, presence of a capsule, bonding tendency, motility, respiration, growth medium, and whether it is intra- or extracellular.
How do you identify a fungal colony?
Surface – how does the surface of the colony appear? For example, smooth, glistening, rough, wrinkled, or dull. Opacity – for example, transparent (clear), opaque, translucent (like looking through frosted glass), etc. Colour (pigmentation) – for example, white, buff, red, purple, etc.
What Colour is fungi?
The colony colour varying from creamy white to suedelike colour with a peripheric margin of brilliant lemon-yellow due to the presence of a pigment which diffuses in agar, is so characteristic as to be pathognomonic (Figure 6)
What is an example of a fungal infection?
Fungal skin infections can happen anywhere on your body. Some of the most common are athlete’s foot, jock itch, ringworm, and yeast infections
What are the 4 characteristics of fungi?
Characteristics of Fungi
- Fungi are eukaryotic, non-vascular, non-motile and heterotrophic organisms.
- They may be unicellular or filamentous.
- They reproduce by means of spores.
- Fungi exhibit the phenomenon of alternation of generation.
- Fungi lack chlorophyll and hence cannot perform photosynthesis.
How do you identify fungi?
Fungi are identified by their morphology in culture. Fungi have mycelium and spores which are used in the identification. Therefore you have to search for mycelium (hyphae), the spores, origin of the spores, asexual or sexual; and their structure and morphology.
What is the major distinguishing characteristic of fungi?
Fungi are eukaryotic organisms means they have true nucleus which are enclosed in membranes. They are non-vascular organisms. They do not have vascular system
What is true of all fungi?
[a] all fungi have (1)cell walls made of chitin & are (2) heterotrophic by absorption. [b] most fungi are [1] multicellular (except yeast & class cyhtrids). It’s true that plants, animals & fungi can all trace their ancestry to protists, however at some points these organisms evolved differently.
Why do fungi reproduce asexually?
The majority of fungi can reproduce both asexually and sexually. This allows them to adjust to conditions in the environment. They can spread quickly through asexual reproduction when conditions are stable
How do spores work?
Spore, a reproductive cell capable of developing into a new individual without fusion with another reproductive cell. Spores are agents of asexual reproduction, whereas gametes are agents of sexual reproduction. Spores are produced by bacteria, fungi, algae, and plants.