## Why is serial dilution necessary in serology?

Serial dilution only allows the reduction of bacteria/cells but not the separation of bacteria/cells like in other techniques like flow cytometry. This technique also requires highly trained microbiologists and experts in aseptic techniques.

How do you calculate serial dilutions?

In serial dilutions, you multiply the dilution factors for each step. The dilution factor or the dilution is the initial volume divided by the final volume. For example, if you add a 1 mL sample to 9 mL of diluent to get 10 mL of solution, DF=ViVf = 1mL10mL=110 .

### What is serial dilution in immunology and serology?

Serial dilution is a common technique used in many immunologic procedures. A small amount of serum or solute can be serially diluted by transferring aliquots to diluent. One of the most common series doubles the dilution factor with each transfer (1:2, 1:4, 1:8 …).

Why are serial dilutions more accurate?

The more evenly spaced the calibration standards are over this range, makes the results of the analysis more reliable. Evenly spaced calibration standards are easier to prepare using serial dilution.

#### How do you calculate CFU ml from serial dilution?

1. To find out the number of CFU/ ml in the original sample, the number of colony forming units on the countable plate is multiplied by 1/FDF. This takes into account all of the dilution of the original sample.
2. 200 CFU x 1/1/4000 = 200 CFU x 4000 = 800000 CFU/ml = 8 x 10.
3. CFU/ml in the original sample.

How is serial dilution used in healthcare?

It is a method of dissolving any substance in the solution in a stepwise manner. Therefore, this type of dilution is very important to make a solution that has high dilution and is less concentrated. The serial dilution is also very useful in avoiding the use of a pipette in order to make the solution diluted.

## What are the limitations of serial dilution?

Serial dilution processes face two major challenges. The first is error propagation across columns or rows. With each sequential serial dilution step, transfer inaccuracies lead to less accurate and less precise dispensing. The result is that the highest dilutions will have the most inaccurate results.

What are two possible errors associated with serial dilution?

There are many potential sources of error. Examples include: incorrect measuring of the sample or diluent; insufficient mixing; not switching pipettes between each step of the serial dilution; contamination because of poor sterile technique; or inadequate mixing of sample and molten agar in the Petri dish.

### What does CFU mL tell you?

The colony forming unit (CFU) is a measure of viable colonogenic cell numbers in CFU/mL. These are an indication of the number of cells that remain viable enough to proliferate and form small colonies.

What does CFU mL mean?

colony-forming unit per millilitre
cfu stands for colony-forming unit. This means that cfu/g is colony-forming unit per gram and cfu/ml is colony-forming unit per millilitre.