Serial Dilutions (2024)

FAQs

Serial Dilutions? ›

A serial dilution definition is a stepwise series of dilutions that are performed to reduce the concentration of a substance in a solution to a more usable concentration.

To complete a tenfold dilution, the ratio must be 1:10. The 1 represents the amount of sample added. The 10 represents the total size of the final sample. For example, a sample size of 1 ml is added to 9 ml of diluent to equal a total of 10 ml.

Serial dilutions result in the geometric progression of the concentration in a logarithmic fashion, meaning the concentration decreases by the same quantity in each successive step.

Answer: 1:5 dilution = 1/5 dilution = 1 part sample and 4 parts diluent in a total of 5 parts. If you need 10 ml, final volume, then you need 1/5 of 10 ml = 2 ml sample. To bring this 2 ml sample up to a total volume of 10 ml, you must add 10 ml - 2 ml = 8 ml diluent.

A general rule to use in calculating the concentration of solutions in a series is to multiply the original concentration by the first dilution factor, this by the second dilution factor, this by the third dilution factor, and so on until the final concentration is known.

Commonly used dilutions are 1:10 or 1:2. Note that this is expressed as the ratio of the previous solution to the final volume of the dilution. For example, to make a 1:10 dilution, you add 1ml of your solution to 9ml of diluent for a final volume of 10ml.

A ten-fold dilution is sometimes also written as a 1:10 dilution. Here 1:10 shows the ratio between the stock and the final volume of the working solution (100 mL : 1000 mL -> 1:10).

Serial dilution involves the process of taking a sample and diluting it through a series of standard volumes of sterile diluent, which can either be distilled water or 0.9 % saline. Then, a small measured volume of each dilution is used to make a series of pour or spread plates.

A serial dilution is a step-wise series of dilutions, where the dilution factor stays the same for each step. The purpose of a serial dilution is to estimate the concentration of a sample, or to obtain the desired concentration of a reagent, chemical or compound.

Mixing is essential for an accurate serial dilution. A mixing step using half the total volume of the intermediate step introduced after every transferring step ensures an accurate and consistent serial dilution.

What does 1 part to 10 parts water mean? ›

A ratio of 1:10 means add 1 part of product to 10 parts of water. A ratio of 1:25 means add 1 part of product to 25 parts of water. Example: to mix a product with a ratio of 1:10 measure: 1 capful of cleaning product and add it to. 10 capfuls of water.

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 .

Answer and Explanation:

A dilution means that we have 1 part sample per 20 parts total volume. We need 5 mL of total volume. We can use cross multiplication, as seen in the illustration below, to determine the amount of sample required.

Serial dilution has many advantages: the materials necessary are typically already present in the lab and require no special engineering. Conditions can be adjusted as the experiment progresses (e.g., drug concentrations increased as drug resistance improves).

We can relate the concentrations and volumes before and after a dilution using the following equation: M₁V₁ = M₂V₂ where M₁ and V₁ represent the molarity and volume of the initial concentrated solution and M₂ and V₂ represent the molarity and volume of the final diluted solution.

The purpose of making and testing serial dilutions is to achieve a “countable” number of plaques in the cell monolayer. If too many infectious particles are present, individual cells are likely to be infected with more than one virion or individual plaques will merge to form large areas lacking cells.