What is the difference between streak plate and pour plate

Streak plate produces surface colonies while the pour plate produces both surface and subsurface colonies. Moreover, streak plate is important for the isolation of bacterial cultures by preparing distinct colonies while the pour plate is important for the quantification of colonies in a solid medium.

The main disadvantage of streak plate is the higher probability of contamination while the main disadvantage of pour plate is microbes have to withstand the temperature of the melted nutrient broth during preparation. Streak plate is a technique in microbiology used to isolate colonies from a culture. In this technique, a loopful from the bacterial slant is systematically streaked on a nutrient broth.

Therefore, it produces surface colonies. Also, this method is important to isolate pure species from a mixture. On the other hand, pour plate is another technique in microbiology used to count colonies. Here, the sample of bacteria is suspended in a Petri dish using melted nutrient agar.

Therefore, it produces both surface and subsurface colonies. Moreover, it is important to quantify the colony-forming bacteria. However, the main difference between streak plate and pour plate is the method and importance.

Figure 1: Streak Plate. In respect to this, how does your calculated CFUS based on pour plate differ from spread plate? When properly done, pour - plate method generally produces distinct colonies while most culturing involving spread plate yields confluent growths. Pour plate method is usually the method of choice for counting the number of colony-forming bacteria present in a liquid specimen.

Loss of viability of heat-sensitive organisms coming into contact with hot agar. Embedded colonies are much smaller than those which happen to be on the surface. 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.

Why does the plate count have an advantage? It takes into account only viable live bacterial cells, giving a closer approximation to the actual number of cells present, whereas counting cells with a microscope wouldn't distinguish living cells from dead cells. The main difference between streak plate and pour plate is that in streak plate , the first to be added is the melted nutrient agar and the second to be added is a loop of bacteria from a slant, whereas the first to be added in pour plate is the bacterial broth and the second to be added is the nutrient agar.

Why is it necessary to use only diluted cultures that contain to cells for a successful spread plate? Spread plate technique is a method employed to plate a liquid sample for the purpose of isolating or counting the bacteria present in that sample.

A perfect spread plate technique will results visible and isolated colonies of bacteria that are evenly distributed in the plate and are countable. Why do you label plates on the bottom , not on the lid? So, it is easier to read the label on the bottom. Petri plates are incubated upside down agar on top to lessen the risk of contamination from settling airborne particles and to prevent water condensation from accumulating and disturbing the cultured microbes.

Look for signs of fungal contamination. Fungal contamination will appear as fuzzy, filamentous, or hair-like growths, and should be visible to the unaided eye. Fungal contamination often occurs right along the edge of an agar plate. Inspect for signs of bacterial contamination. For safety reasons, plates and equipment should be sterilised after use. Answer Expert Verified. If plates are poured with agar that is too hot, then the agar would kill the bacteria.

Therefore, enumeration will be easy in this technique if the dilution is correct. According to the recommendation, the plates which have 30 to colonies are selected for enumeration.

Using an equation, we can do the correct quantification after enumeration. Streak plate technique allows you to isolate and purify bacteria. On the other hand, spread plate technique allows you to enumerate bacteria.

This is the key difference between streak plate and spread plate. Furthermore, we can use an inoculating loop or cotton swab as an inoculating tool in streak plate while we need a spreader for spread plate technique.

A loopful of the sample is the quantity that draws from the sample in the first technique while 0. Inoculum introduces into a fresh medium by drawing zig-zag pattern lines in streak plate while the inoculum spreads evenly throughout the surface in the spread plate. Streak plate and spread plate are two microbial techniques perform in bacteriology. Streak plate facilitates isolation and purification of a specific bacterium while spread plate facilitates enumeration of bacteria in a sample.

Both methods are highly useful for bacterial studies, especially for aerobic bacteria. Streaks in a zig-zag pattern are done in a streak plate while the inoculum is evenly spread on the surface of the medium in spread plate. This is the difference between streak plate and spread plate. Available here 2. Available here.