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Dilution is done to decrease the amount of colonies found in the plates. If the solution is not diluted, it would be difficult to count the number of colonies because they would all overlap one another. So by dilution, we can limit the amount of colonies overlapping each other, count them, and used this number to estimate the number of bacteria in the original sample.
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Why dilution is a common approach employed by any pure culture technique?
the main purpose of this is to grow and isolate all bacteria present in an infection, to determine which of the bacteria that grew are most likely causing the infection and which are likely colonizers.
How do you do a serial dilution of a specific concentration of culture?
bacterial cell numbers needs reducing ,which is done by repeatedly diluting the amount of you have in your sample. A small amount of bacterial sample is mixed with a diluent solution(such as sterile broth), and then dilution are made. by adding small amount of diluted bacteria samples then spread onto the agar plate by L-shaped glass rod.
What is a ten fold serial dilution?
Serial dilution is usually 1/10 dilution. Therefore after a series of dilutions, you have a logarithmic curve of concentration (log10). Basically, if diluting 1/10 and starting off with 1 molar solution, first dilution = 0.1M, 2nd = 0.01M, 3rd = 0.001M. If making a 0.001M solution involved weighing out 0.005g of a salt for example, the error in making this solution out would be very large in comparison to weighing out 5g (1M) and diluting it 3 times by serial dilution. The benefit of it is mainly accuracy.
How do you determine the number of organisms in a water sample if your dilution plate has presence of spreading colonies?
To determine the number of organisms in a water sample choose a plate that has less than 300 but more than 30 colonies. Then count the number of colonies and record the results.
Why is it necessary to use a fresh tip for each transfer when making dilutions?
Let's imagine what happens if you use your contaminated tip from the last dilution: You wouldn't only transfer cells from the diluted solution, but also take some cells that stick on the tip to your next dilution. So in effect, you will have more cells in the new dilution than you would expect - and your experiments results are improper.
Why sample need to be diluted?
why the sample need dilution
What is the importance of dilution?
To reduce the concentration or number of microbes in a sample
What is the explanation for tenfold dilution technique?
In ten fold dilution we add one part of the sample into the nine part of the diluent e.g. water. It will make it ten fold dilute. If we have series of tubes to dilute then after making the ten fold dilution in first tube, take the dilute sample from the first tube in same quantity as we added sample in first tube and add it to 2nd one. then then take the same quantity from 2nd one and add to third one and so on......... from the last tube we take the adjusted quantity of dilute sample and discard it. This will make the series of ten fold dilution. If you add one part substance to 10 parts of water, you get an 11-fold dilution.
To prepare 300 ml of a 115 dilution from a 13 dilution you need to add ml of the 13 dilution to ml of diluent?
33,4ml
What is the formula for dilution factor?
Dilution factor is the final volume / aliquot volume. Aliquot volume is the measure of sub volume of original sample. Final volume is the total volume. Dilution factor =final volume /aliquot vol. for example ; what is the df when you add 2ml sample to 8m??? total vol is 2+8=10 DF=total vol/aliquot. 10/2=5 So 5 is dilution factor
Can diluted urine give a false negative?
If you deliver a diluted sample, they'll flunk you just for the dilution.
Why is a 20-gram sample of hamburger blended with 180 ml of diluent to yield a 110 dilution before making further dilutions?
20 grams is equivalent to 20ml. 20ml(sample) +180ml(diluent) = 200ml. 20ml is 10th part of 200ml. Ratio will yield a 1:10 dilution.
Why dilution is a common approach employed by any pure culture technique?
the main purpose of this is to grow and isolate all bacteria present in an infection, to determine which of the bacteria that grew are most likely causing the infection and which are likely colonizers.
How do you do a serial dilution of a specific concentration of culture?
bacterial cell numbers needs reducing ,which is done by repeatedly diluting the amount of you have in your sample. A small amount of bacterial sample is mixed with a diluent solution(such as sterile broth), and then dilution are made. by adding small amount of diluted bacteria samples then spread onto the agar plate by L-shaped glass rod.
A sample of rainwater is tested with a universal indicator so what does this tell you about rainwater?
A liquid dilution system which dilutes a sample to be analyzed with a carrier to supply a diluted sample-containing liquid to an analytical measurement apparatus of flow type. The inventive dilution system features simplicity and versatility as compared to conventional automatic apparatus with robot concept, and the present system comprises: a first carrier pump for feeding a first carrier; a sample injection unit for injecting the sample into the first carrier; a main passage for flowing a liquid from the sample injection unit to a detector unit of an analytical measurement apparatus; a branching device located downstream of the sample injection unit for forming a branched passage to remove a liquid mass partially from the main passage; a confluence unit located downstream of the branching unit for confluencing a second carrier; and a second carrier pump for feeding the second carrier to the confluence unit. Dilution and mixing of the sample with a carrier is done twice, once at the sample injection and then again at confluence.
What are the main sources of error in a BOD test?
1. dilution error 2.blame the test sample 3.poor maintenance of bottles(cleaning)
How does one prepare a 1100 dilution?
1 part of solution A plus 99 parts solution B
