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How would you check the purity of an isolated colony that was picked off a streak plate?
Wiki User
∙ 6y ago
It can be done by subculturing the culture on agar plate. The best way for this is streaking the culture which will separate the two different organisms.
If the organisms are known then specific differential media or selective media can be used which will indicate specific different colonial characteriszation. Allthough this can be done even if the organisms are unknown so that probability are there if they show different characters.
Wiki User
∙ 12y ago
Wiki User
∙ 14y agoYou can check the purity of a culture or a colony by first diluting the colony and then sub-culturing by streaking on the proper media and then incubating it for the required period of time.After you see colonies on the media,pick up each and every colony and check for its gram character,motility,check its morphological and cultural characteristics.It should be one and the same.
Wiki User
∙ 11y agoA pure culture, which contains only one type of organism can be confirmed by smear staining or simple staining a small amount (loopfull) of the organism and looking at it under the microscope. Depending on what stain you use (Nigrosin or Safranin) you will be able to tell whether the cell is gram - or gram + and whether or not the organism is "pure".
Wiki User
∙ 6y agoYou can start an other streak on a second plate to see if you get just one type. If you were very careful when you first made your streak plate so you got several single colonies, you will be ok. It all depends too on how important the ID is and how strict your lab is. Sometimes knowing exactly what something is can be life saving.
Wiki User
∙ 14y agoYou can tell it's pure if no other bacteria but the one you are isolating is present.
Wiki User
∙ 12y agoBiochemical typing
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If an inoculated plate had colonies between the streak lines what would you conclude?
It depends, if there is no growth or colony appearance on streak line and only it shows growth in b/w the streak line then it is certainly a contamination and if there are colonies on streak line and not ressemble with the streak culture then also it is a contamination but there can be a chance that colony appears due to some fault in streaking procedure and the inoculum drops between the streak line so it depends.
What advantage does the streak plate method have over the pour plate method?
A disadvantage of the streak plate technique could be colony isolation problems. If the streaking technique is not done properly or if there is too much of an organism present on the inoculating loop then the cells can cluster and form what looks like one colony but it can actually be a couple colonies (made from a couple cells). This can cause an inaccurate colony forming unit count.
Why does the streaking method you used to inoculate you plates result in isolated colonies?
In the streak plate technique, a loop is used to streak the mixed sample many times over the surface of a solid culture medium in a Petri plate. Theoretically, the process of streaking the loop repeatedly over the agar surface causes the bacteria to fall off the loop one by one and ultimately to be distributed over the agar surface, where each cell develops into a colony.
Why use a streak plate to grow a bacterium?
You do a streak plate in order to get isolated colonies. If you inoculate into a slant, you have less surface area to work and less chance of getting isolated colonies. In broth, you'll definitely get growth but you won't know WHAT is growing. You go back into each quadrant (a little) with your loop in order to "dilute" the bacteria and get colonies. Quadrant 1 is pretty think (like a smear on the plate) but by the time you get to Quadrants 3 and 4, you should see more defined colonies and not just a film of bacteria.
How would you determine whether a colony was a contaminant on a streak plate?
One to determine whether a colony on a streak plate is a contaminant is by observing whether it is located along the streak lines. Another is to compare the size, shape, texture and color of the colony against an uncontaminated sample to see if it matches previous ones. Anything growing beyond streak lines and outside of the expected pattern of growth is an obvious contaminant.
Why must have 4 part in streaking technique?
so that you can get isolated colonies in the last streak . . . As you streak contineously you inoculum quantity decreases . . there by when you reach the end of last streak you get separate and isolated colonies . .
What is the purpose of the streak for isolation?
By using streak plate technique to spread a clinical sample out on the surface of a growth medium individual types of bacteria can be isolated
If an inoculated plate had colonies between the streak lines what would you conclude?
It depends, if there is no growth or colony appearance on streak line and only it shows growth in b/w the streak line then it is certainly a contamination and if there are colonies on streak line and not ressemble with the streak culture then also it is a contamination but there can be a chance that colony appears due to some fault in streaking procedure and the inoculum drops between the streak line so it depends.
Will isolated colonies always be in the second sector on the streak plate?
No. It depends on the number of bacteria present in the initial sample. If the number of bacteria in the initial sample are limited, you may get isolated colonies in the first streak. If the number of bacteria in the sample are high, it may take several streaks before the sample is diluted to the point where isolated colonies are evident.
What is the main advantage of T-streak?
The main advantage of T- streak method: 1. To get a very good isolated colonies.2. To obtain pure culture from mixed culture.
What is the main advantage of T streak?
The main advantage of T- streak method: 1. To get a very good isolated colonies.2. To obtain pure culture from mixed culture.
Why is straight needle preferable to a loop for obtaining inoculum from the streak plate culture?
Technically because the loop has greater surface area and you have a chance of touching more than one colony. That is very hard to do with a needle. Still, if you turn your loop on edge and dab like a needle it will do the job just as well. Also, if you have any competence at all your streak plate will have well isolated colonies in the 3rd/4th streak making this question pointless.
Why is a straight needle preferable to a loop for obtaining inoculum from streak plate culture?
Technically because the loop has greater surface area and you have a chance of touching more than one colony. That is very hard to do with a needle. Still, if you turn your loop on edge and dab like a needle it will do the job just as well. Also, if you have any competence at all your streak plate will have well isolated colonies in the 3rd/4th streak making this question pointless.
How you differentiate between Transformed bacterial colonies and satellite colonies?
Re-streak the center of the 'star' colony (transformed surrounded by satellites) on a plate contains the antibiotic, typically ampicillin. The colonies in the tertiary streak will most likely be the transformants. If you want to be quite sure, pick a single colony from the tertiary streak and re-streak again on a plate containing the antibiotic.
What advantage does the streak plate method have over the pour plate method?
A disadvantage of the streak plate technique could be colony isolation problems. If the streaking technique is not done properly or if there is too much of an organism present on the inoculating loop then the cells can cluster and form what looks like one colony but it can actually be a couple colonies (made from a couple cells). This can cause an inaccurate colony forming unit count.
Why is mineral's streak more useful in identifying a mineral than its color?
Because color can vary based on the purity of the mineral.
Can you identify a mineral by its physical properties?
Color, reflectivity, purity. Just to name a few.
