Asked by: Maple Hormaechea
medical health infectious diseases

Why is the streak plate so important in the production of pure cultures?

Last Updated: 30th March, 2020

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Purpose of streaking
To produce isolated colonies of an organism (mostly bacteria) on an agar plate. This is useful when we need to separate organisms in a mixed culture (to purify/isolate particular strain from contaminants) or when we need to study the colony morphology of an organism.

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Simply so, what is the importance of the streak plate method?

Streak plate technique is used to grow bacteria on a growth media surface so that individual bacterial colonies are isolated and sampled. Samples can then be taken from the resulting isolated colonies and a microbiological culture can be grown on a new plate so that the organism can be identified, studied, or tested.

Secondly, why is it important to obtain isolation of bacteria into pure culture? The isolation of bacteria in pure culture is important because it facilitates the application of recombinant DNA technology through the isolation of clones.

Keeping this in view, why is it important to make pure cultures?

The importance of having a pure culture, and not a mixed culture, when performing biochemical testing is that a pure culture may react much differently in isolation than when it is combined with other species. Bacteria replicates at infinitesimally long rates and one species may enforce or weaken the other.

What are three methods commonly used to derive a pure culture?

Such isolated colonies are picked up separately using sterile inoculating loop/needle and re-streaked onto fresh media to ensure purity.

  • Pour Plate Method:
  • Spread Plate Method:
  • Serial Dilution Method:
  • Single Cell Isolation Methods:
  • Enrichment Culture Method:

Related Question Answers

Asiel Ninni

Professional

What is a disadvantage of the streak plate technique?

Disadvantages ? There is a Higher Probability of Contamination prior to isolation. ? Streak plate method can be used for qualitative and not quantitative studies because it cannot be used for the enumeration of the approximate number of bacteria in the given sample.

Caryl Arispon

Professional

What is the application of streak plate and dilution plate?

Streak plate technique is used for the isolation into pure culture of the organisms (mostly bacteria), from mixed population. The inoculum is streaked over the agar surface in such a way that it “thins out” the bacteria. Some individual bacterial cells are separated and well spaced from each other.

Anders Areal

Professional

What are pure cultures?

A pure (or axenic) culture is a population of cells or multicellular organisms growing in the absence of other species or types. A pure culture may originate from a single cell or single organism, in which case the cells are genetic clones of one another.

Fengmei Virgasov

Explainer

What is the difference between a streak plate and a spread plate techniques?

Difference Between Streak Plate and Spread Plate. The key difference between streak plate and spread plate is that the streak plate is used to isolate and purify a particular bacterial species from a mixture of bacteria while the spread plate is used to enumerate and quantify bacteria in a sample.

Alharilla Karnoupakis

Explainer

What is the principle of streak plate method?

Principle. The streak plate technique is the most popular method for isolating specific bacteria from a sample containing a mixture of microorganisms. The technique essentially dilutes the number of organisms and reduces their density. It allows microbiologists to distinguish and isolate individual bacterial colonies.

Glen Trevilla

Explainer

What is a pure colony?

A pure colony or culture (in microbiology) is a laboratory culture containing a single species of organism. Isolation of a pure culture may be enhanced by providing a mixed inoculum with a medium favouring the growth of one organism to the exclusion of others.

Evencia Yaba

Pundit

What is T streaking?

The three-phase streaking pattern, known as the T-Streak, is recommended for beginners. The streaking is done using a sterile tool, such as a cotton swab or commonly an inoculation loop. When the loop is cool, it is dipped into an inoculum such as a broth or patient specimen containing many species of bacteria.

Tiziana Iscar

Pundit

What methods can be used to isolate bacteria?

Isolate single bacterial colonies by the streak-plating method. Use pour-plating and spread-plating methods to determine the concentration of bacteria. Perform soft agar overlays when working with phage. Transfer bacterial cells from one plate to another using the replica-plating procedure.

Zobia Tsevlovsky

Pundit

How can you identify a pure culture?

Pure cultures are the presence of single, isolated colonies of the same type. You can confirm purity by preparing a smear and looking under the microscope. In regard to bacterial growth on solid media, define the term "colony".

Daniele Bentos

Pundit

Touriya Gistau

Pundit

What are pure culture techniques?

A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. A pure culture may originate from a single cell or single organism, in which case the cells are genetic clones of one another.

Edileuza Larreche

Teacher

How do you maintain a pure culture?

These methods include refrigeration, paraffin method, cryopreservation, and lyophilization (freeze drying).
  1. Periodic Transfer to Fresh Media.
  2. Refrigeration.
  3. Paraffin Method/ preservation by overlaying cultures with mineral oil.
  4. Cryopreservation.
  5. Lyophilization (Freeze-Drying)
  6. Advantage of Lyophilization.

Agata Masllorens

Teacher

What is the difference between a pure culture and a pure colony?

When we count the number of colonies on a plate, we are determining the number of cells that were plated on the plate BECAUSE 1 COLONY COMES FROM ONE CELL THAT DIVIDES EXPONENTIALLY. A pure culture is a culture that is derived from 1 bacterial cell so it contains only 1 species.

Dinesh Bizcocho

Teacher

What is the purpose of slant culture?

Slanting the surface of the agar gives the bacteria a greater surface area on which to grow in a test tube. Furthermore, slants are created in test tubes that can be capped, which minimizes water loss. This is important because of the high moisture content of agar media.

Aleidis Ferrusola

Teacher

What is the purpose of isolating bacteria?

Isolation is done to obtain pure bacterial cultures. Pure culture is essential in the study of the morphology, physiology, biochemical characteristics, and susceptibility to antimicrobial agents of a particular bacterial strain.

Shalanda Malquartu

Reviewer

Why would we want to achieve individual colonies?

It is important because you want to have a pure colony, you don't want mixed colonies, you essentially want to study one genera of bacteria not multiple. This is important to study the genes of that genera of bacteria or the specific characteristics of that bacteria.

Yasser Grew

Reviewer

What is a mixed culture?

In the study of microorganisms, a mixed culture is one that contains more than one type of organism growing in a sterile medium, such as agar. The mixed culture can include multiple species of viruses, bacteria and parasites, which may or may not live in harmony with one another, sharing the available resources.

Amale Ravina

Reviewer

How do you identify a colony of microorganisms?

Different types of bacteria produce different-looking colonies, some colonies may be colored, some colonies are circular in shape, and others are irregular. A colony's characteristics (shape, size, pigmentation, etc.) are termed the colony morphology. Colony morphology is the way scientists identify bacteria.

Laurence Lahlou

Reviewer

What is a contaminated culture?

contaminated culture. A culture in which bacteria from a foreign source have infiltrated the growth medium.