Quick Answer: What Would Happen If Plates Were Incubated A Week Longer?

Can some bacteria grow on the streak plate and not be seen if the pour plate technique is used?

Could some bacteria grow on the streak plate not be seen using the pour plate technique.

Yes, aerobic organisms will not grow in the pour plate, they may still grow on a streak plate.

To determine the number of bacteria in an original sample, a pour plate must have between, 25 and 250 colonies selected..

What is a disadvantage of the pour plate technique?

Disadvantages of Pour plate method Preparation for pour plate method is time consuming compared with streak plate/and or spread plate technique. 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.

What is the purpose of flaming the loop between streaks areas?

Flaming the loop between streaks ensures that the loop starts clean and that only this small amount of bacteria is used to inoculate the next quadrant.

What is the difference between streak plate and spread plate technique?

Successful streaks lead to individual colonies of microbes. In microbiology, streaking is a technique used to isolate a pure strain from a single species of microorganism, often bacteria. … Spread plates are simply microbes spread on a media plate. Microbes are in a solution, and can be diluted.

Why do you label the bottom of the agar plate?

Why do you label plates on the bottom, not on the lid? After the culture medium is set, and streaked with the required microbe/stock, the lid is put on and the petri dish is incubated upside down to minimize contamination. So, it is easier to read the label on the bottom.

How could your streak plate technique be improved?

How could your streak plate method be improved? Because the purpose of a streak plate is to obtain isolated cultures from an inoculum, consider using a fourth quadrant to further increase the probability of isolated cultures.

Will the isolated colonies always be in the fourth sector on the streak plate?

Sometimes bacteria will clump together and look like a colony when they are not. Will the isolated colonies always be in the fourth sector on the streak plate? No, sometimes you might get them in the third but usually not the fourth because they’re all so clumped together.

How could you tell if there were any contaminants on your Streak plate?

If the plate has not been inoculated, the presence of any bacterial colonies indicates contamination. On an inoculated plate, look for colonies that display morphology different than what you would expect from the type of bacteria used to inoculate the plate.

Why agar plates are incubated upside down?

Petri dishes need to be incubated upside-down to lessen contamination risks from airborne particles landing on them and to prevent the accumulation of water condensation that could disturb or compromise a culture.

Was the streak plate method effective at diluting the population size in both plates?

The streak plate method was effective at diluting the population size in all four plates because it is a rapid isolation method and it also allowed for easier observation of the bacteria. The streak plate method is also a useful tool for obtaining the color of certain substances.

What is the purpose of a pour plate?

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 foodstuffs.

What is the difference between spread plate and pour 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 thespread plate. … Both require Petri dishes and nutrient agar.