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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.
What else can I help you with?
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.
How could you tell if one of the colonies on the plate was a contaminant that fell in from the air?
If one of the colonies was to be contaminated by something in air, you would be able to tell by there being a difference in look for specimen. Also looking to see if something is growing on top of smooth specimen.
How would you check the purity of an isolated colony that was picked off a streak plate?
Well, isn't that a happy little question! To check the purity of your isolated colony, you can simply pick a small amount of the colony and streak it onto a fresh agar plate. If only one type of colony grows on the new plate, then your original colony is likely pure. Just remember, there are no mistakes, only happy little accidents in science!
How could you identify a potential contaminant on a streak plate?
To clean a streak plate I use coke classic. In the red can, the diet version does not work as well. I believe it is the acid that takes away the powdered rock debris. It makes them quite white again. Mr clean magic eraser also takes away some of the heavy debris...but does not get them clean enough.
When would a microbiologist want to use the streak-to-grow method.?
Plate streaking is often done to isolate a colony of bacteria. For instance, if a broth was grown with 2 or 3 different types of bacteria, it could be streaked out in a "3-phase streak." In a 3-phase streak the initial streak takes up a very small area (we draw a T on the back of the plate, this streak goes in the section above the T). The loop is flamed to kill off any bacteria still on it, then a couple streaks are made out of the original. This grabs some of the bacteria from that concentrated streak and spreads them out. This is repeated once more until the final streaks are less and less concentrated bacteria. When we incubate the plate we'll find lots of growth where the original streak was and less and less as we follow the path of the 3-phases. What you're looking for now is a single colony, off by itself. This can then be scraped off and plated on a separate plate and considered a "pure colony." Another usual time to use streak-to-grow bacteria is when you want to know the quantity or concentration of bacteria. You take maybe 0.1mL of solution and plate it, then count the number of colonies that form. Say you have 56 colonies, now you can say: 56 cfu (colony forming units) -------- 0.1 mL or 560 cfu/mL This is usual when testing to see whether a sterilization technique worked, or if a product is within the regulated levels of bacteria to be released the public, etc etc.
How do you determine the streak of a mineral and why is streak a useful property?
you see and feel how shiney it is
How do you determine the streak of a mineral whose Mohs scale is higher than the streak plate?
You can determine the streak of a mineral whose Mohs scale is higher than the streak plate by either filing or crushing with a hammer before rubbing the sample on a streak plate.
How do you determine minerals streak?
The color of a mineral in powdered form is called the mineral's Streak
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 properties would you use to determine whether two minerals are different minerals?
You could use the streak color, whether it has cleavage or fracture, the texture, the luster, the hardness, the color, and lots of different properties.
What properties to would you use to determine whether to mineral samples are different minerals?
You could use the streak color, whether it has cleavage or fracture, the texture, the luster, the hardness, the color, and lots of different properties.
Why could the streak of corundum be difficult to determine?
Corundum has a streak that is typically colorless, making it difficult to determine on a streak plate. The hardness of corundum (9 on the Mohs scale) can also affect the accuracy of the streak test, as it can scratch the streak plate instead of leaving a distinct streak.
What properties would use to determine whether two mineral samples are different minerals?
You could use the streak color, whether it has cleavage or fracture, the texture, the luster, the hardness, the color, and lots of different properties.
Would the streak of garnet be difficult to determine?
Determining the streak of garnet can be challenging because it varies depending on the specific type of garnet. In general, garnet typically has a white streak, but some varieties may leave a slightly different colored streak due to impurities. It's best to use a streak test plate to compare and determine the actual color of the streak.
What is the purpose of the plate?
A streak plate is used to determine the streak colour of a mineral. You take the mineral and scratch it against the streak plate, and it will create a coloured streak on the plate. The streak is not always the same colour as the mineral itself.
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.
Why is streak an important physical property of minerals?
A streak test is used to determine a minerals streak color. This can help in the identification of minerals.
