What is the difference between pour plate and spread plate?

What is the difference between pour plate and spread plate?

The main difference between pour plate and spread plate is that the molten agar is poured on to the inoculum during the preparation of the pour plate whereas inoculum is spread on the surface of the solidified agar during the preparation of the spread plate. Both require Petri dishes and nutrient agar.

Why do we use pour plate technique?

The pour plate technique can be used to determine the number of microbes/mL in a specimen. It has the advantage of not requiring previously prepared plates, and is often used to assay bacterial contamination of food stuffs.

How do you spread bacteria in your lawn?

Bacterial lawns can be produced manually by evenly spreading a high amount of bacteria onto an agar plate using a sterile cotton swab or a Drigalski spatula. Alternatively an automated machine can be used such as a spiral plater where the plate is rotated and the sample is spread evenly using an automated dispenser.

Where do colonies grow in pour plates?

Pour plates allow micro-organisms to grow both on the surface and within the medium. Most of the colonies grow within the medium and are small in size and may be confluent. The few colonies that grow on the surface are of the same size and appearance as those on a streak plate.

What precautions will you take when performing pour plate method?

11 Pour Plate Method Best Practices

  1. Keep the molten agar in the water bath for no more than three to four hours.
  2. Don’t re-melt the agar.
  3. Use phosphate buffer pH 7.2 if necessary to dilute the suspension.
  4. Decrease the risk of contamination by pouring plates in a laminar-airflow cabinet.

What must be done to a sample before the pour plate technique is performed?

What must be done to a sample before performing the pour-plate technique? Broth culture must be added to the sample. Colony-forming units must be separated by performing serial dilutions.

What is a lawn plate used for?

Spread or ‘lawn’ plates should result in a heavy, often confluent growth of culture spread evenly over the surface of the growth medium. This means they can be used to test the sensitivity of bacteria to many antimicrobial substances, for example, mouthwashes, garlic, disinfectants and antibiotics.

What are the disadvantages of spread plate technique?


  • Spread plate method allows the growth of other microbes along with desired Microbes.
  • In this method the volume of sample not greater than 0.1 ml can be spread on the nutrient agar plate because it would not soak well and may result in colonies to coalesce as they form.

How do you sterilize plate spreaders?

Sterilization. Before using a cell spreader, if the spreader is made from glass or metal, researchers must sterilize the spreader by submerging it in alcohol or ethanol and later burning the alcohol off by placing the spreader in a Bunsen burner flame to eliminate microorganisms.

What’s the best way to make a spread plate?

Dip the L-shaped glass spreader (hockey stick) into alcohol. Flame the glass spreader over a bunsen burner. Spread the sample evenly over the surface of agar using a cool alcohol-flamed glass rod spreader, carefully rotating the Petri dish underneath at an angle of 45 o at the same time. Incubate the plate at 37°C for 24-48 hours.

How is the spread plate culture technique used?

PRINCIPLE OF SPREAD PLATE CULTURE TECHNIQUE. The spread plate culture method is one of the commonly used culture technique for the isolation of microorganisms, especially the bacteria, in the laboratory. In this technique, a serially diluted specimen containing 2 or more bacteria or microbe

How to make an agar plate with a spreader?

Procedure of Spread Plate Technique 1 Make a dilution series from a sample. 2 Pipette out 0.1 ml from the appropriate desired dilution series onto the center of the surface of an agar plate. 3 Dip the L-shaped glass spreader into alcohol. 4 Flame the glass spreader (hockey stick) over a Bunsen burner.

How is spread plating used in a cell?

It is used for viable plate counts, in which the total number of colony forming units on a single plate is enumerated. It is used to calculate the concentration of cells in the tube from which the sample was plated. Spread plating is routinely used in enrichment, selection, and screening experiments.

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