What is Streak Plate technique ?

Streaking is a technique that isolates a pure stress, overload from a species of bacteria. A sample is taken from a colony and a microbiological culture is grown on the new plate in order for the organism to be identified properly.

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It was Loeffler and Gaffky who an initial developed this an approach in Koch’s laboratory.

The procedure entails diluting bacteria by streaking the bacteria over the surface of the agar in the Petri dish. The way, an isolated swarm can it is in obtained and also grow right into a variety of cells. The culture is referred to as a microbiological culture if the organism grow in the agar surface. (1, 2, and 3)


Picture 5: The actual an outcome of a streak bowl technique.

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What is the tools needed because that the streak plate method?

Inoculation loop (6)Bacteria sourceBunsen burnerStriker/lighterAgar bowl (5)LysolPaper towel

What to save in mind once doing a streak key method?

Make certain you use just a small amount of inoculum.Make sure you streak easy so as not to gouge the agar.See to it that the plate’s surface ar is complimentary of droplets of condensed moisture.After streaking each quadrant, do not forget to fire the loop.The inoculum source can be a broth or hard culture, an eco-friendly swab, a clinical specimen, or sedimented urine.The petri food to be used have to be a hundreds millimeter in diameter. (3, 6, 7, and also 8)

What is the purpose of the streak plate technique?

The objective of the streak plate an approach is to create an isolated swarm of an organism on the agar plate. Isolation the the organism is a must in a mixed culture, particularly if you must thoroughly study the nest morphology that a certain organism. (4, 7)

How is the streak plate method done?

The inoculating loop have to be sterilized in the Bunsen burner by just putting the loop into the flame. Wait for the loop to revolve red indicating that it is already hot. Let that cool down for a few minutes.Using the inoculating loop, pick an isolated nest from the agar plate and spread on the very first quadrant the the petri plate. (4, 5)Gently streak the inoculating loop utilizing a ago and soon motion.Put the loop in the flame and let it cool. Expand the streaks right into the second quarter of the petri plate.Repeat action four and also this time expand the streak right into the petri plate’s 3rd quadrant.Repeat action four and also go earlier to the area girlfriend streaked in the third quadrant of the petri plate and this time expand the streak into the fourth quadrant the the petri plate.Flame the loop. (8, 9, and also 10)

Interpreting results

The streaked plate should be incubated because that a full of 24 hrs at a temperature the 37 level Celsius. Very closely examine the swarms grown on the petri plate. The expected result is that all nests must have actually the same general appearance.

If you an alert that there is more than one kind of colony, climate you have to start to streak again however this time top top a separate plate so regarding obtain a pure culture. (4, 5, and also 6)

Streak plate method advantages and also disadvantages


The streak plate technique enables you come select and work through individual colonies.It is the ideal an approach if you are doing basic work through a certain form of microorganism.Through the streak bowl method, friend will end up through a genetically identical individual colony, which makes it basic for you come grab and also transfer colonies for a microscope examination.The streak plate technique is convenient and also hassle-free as you will be able to get clearly shows individual swarms in a single petri plate for as long as you have a good streaking skill. (2, 6, 9, and also 10)


The streak plate an approach does not work with high quantities of organisms. It will certainly not enable you to get a concentration count.It requires substantial storage room and over there is a opportunity that her incubator cannot accommodate a large volume of petri plate.You will be forced to prepare the agar ahead of time. The procedure can be a tedious process, specifically if you don’t know the sample size prior to the rap work.Training and an approach are compelled as various growth media have various densities come the agar. If you room not professional enough, climate you would finish up tearing v the agar, particularly if you use too much pressure ~ above the agar. A dorn streaking technique can destroy your plate.The streak plate method can it is in time-consuming, specifically if you space going to prepare a big sample size.

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It calls for strict maintenance. The streak plate technique will require continuous use of the streaking loop. Eventually, it will wear out and you require to adjust it every as soon as in a while. (2, 5, 7, and also 10)