- Feb 27, 2019 Serial Vs Parallel Dilution. SECOND: Also use a serial dilution when the dilution factor is so large that the amount of stock solution needed to make the dilution in one step (using the formula C 1V 1 = C 2V 2) is too small to measure accurately. Remember that the smallest volume you can measure with the micropipettors is 2 μL.
- Mar 26, 2018 Serial Dilutions. A dilution series is a succession of step dilutions, each with the same dilution factor, where the diluted material of the previous step is used to make the subsequent dilution. This is how standard curves for ELISA can be made. To make a dilution series, use the following formulas: Move Volume = Final Volume / (DF -1).
This section is not a recipe for your experiment. It explains someprinciples for designing dilutions that give optimal results. Onceyou understand these principles, you will be better able to designthe dilutions you need for each specific case.
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Often in experimental work, you need to cover a range ofconcentrations, so you need to make a bunch of differentdilutions. For example, you need to do such dilutions of thestandard IgG to make the standard curve in ELISA, and then againfor the unknown samples in ELISA.
Serial Vs Parallel Dilution Method Of Bod Window Awnings Sound Atomic Packing Factor For Bcc And Fcc All Mobile Price In Pakistan 2018 Blog Gilisoft Universal Keygen. Sep 16, 2019 Serial Vs Parallel Dilution Parallel dilution is the dilution of a solution with equalquantity of the same solvent with which the solution is made. E.g.,1mL of 100µg/ml strength aqueous solution can be diluted to 2mL of50µg/mL strength solution by adding 1mL Water.
You might think it would be good to dilute 1/2, 1/3, 1/10, 1/100.These seem like nice numbers. There are two problems with this series ofdilutions.
- The dilutions are unnecessarily complicated to make. You need to do a differentcalculation, and measure different volumes, for each one. It takes a longtime, and it is too easy to make a mistake.
- The dilutions cover the range from 1/2 to 1/100 unevenly.In fact, the 1/2 vs. 1/3 dilutions differ by only 1.5-fold in concentration,while the 1/10 vs. 1/100 dilutions differ by ten-fold. If you are going tomeasure results for four dilutions, it is a waste of time and materialsto make two of them almost the same. And what if the half-maximal signaloccurs between 1/10 and 1/100? You won't be able to tell exactly where itis because of the big space between those two.
Serial dilutions are much easier to make and they cover the range evenly.
Serial dilutions are made by making the same dilution step over and over,using the previous dilution as the input to the next dilution in each step.Since the dilution-fold is the same in each step, the dilutionsare a geometric series (constant ratio between any adjacent dilutions).For example:
- 1/3, 1/9, 1/27, 1/81
- 1/5, 1/25, 1/125, 1/625
When you need to cover several factors of ten (several 'orders of magnitude') witha series of dilutions, it usually makes the most sense to plot the dilutions(relative concentrations) on a logarithmic scale. This avoids bunching mostof the points up at one end and having just the last point way fardown the scale.
Before making serial dilutions, you need to make rough estimatesof the concentrationsin your unknowns, and your uncertainty in those estimates. For example,if A280 says you have 7.0 mg total protein/ml, and you thinkthe protein could be anywhere between 10% and 100% pure, then yourassay needs to be able to see anything between 0.7 and 7 mg/ml.That means you need to cover a ten-fold range of dilutions, or maybe a bitmore to be sure.
If the half-max of your assay occurs atabout 0.5mg/ml,then your minimum dilution fold is(700mg/ml)/(0.5mg/ml) = 1,400.Your maximum is(7000mg/ml)/(0.5mg/ml) = 14,000.So to be safe, you might want to cover 1,000 through 20,000.
In general, before designing a dilution series, you need to decide:
- What are the lowest and highest concentrations (or dilutions)you need to test in order to be certain of finding the half-max? Thesedetermine the range of the dilution series.
- How many tests do you want to make? This determines the size of theexperiment, and how much of your reagents you consume. More tests will coverthe range in more detail, but may take too long to perform (or cost too much).Fewer tests are easier to do, but may not cover the range in enough detailto get an accurate result.
- What volume of each dilution do you need to make in order to haveenough for the replicate tests you plan to do?
Now suppose you decide that six tests will be adequate (perhapseach in quadruplicate).Well, starting at 1/1,000, you need five equal dilution steps (giving yousix total dilutions counting the starting 1/1,000) that end ina 20-fold higher dilution (giving 1/20,000). You can decide on a goodstep size easily by trial and error. Would 2-fold work? 1/2, 1/4, 1/8, 1/16, 1/32. Yes, in factthat covers 32-fold, more than the 20-fold range we need. (The exact answeris the 5th root of 20, which your calculator will tell you is 1.82 foldper step. It is much easier to go with 2-fold dilutions and gives about thesame result.)
So, you need to make a 1/1,000 dilution to start with. Then you need toserially dilute that 2-fold per step in five steps. You could make 1/1,000 byadding 1 microliter of sample to 0.999 ml diluent. Why is that a poor choice?Because you can't measure 1 microliter (or even 10 microliters) accuratelywith ordinary pipeters. So, make three serial 1/10 dilutions(0.1 ml [100 microliters] into 0.9 ml): 1/10 x 1/10 x 1/10 = 1/1,000.
Now you could add 1.0 ml of the starting 1/1,000 dilution to1.0 ml of diluent, making a 2-fold dilution (giving 1/2,000).Then remove 1.0 ml from that dilution (leaving 1.0 ml for yourtests), and add it to 1.0 ml of diluent in the next tube (giving1/4,000). And so forth for 3 more serial dilution steps (giving1/8,000, 1/16,000, and 1/32,000). You end up with 1.0 ml of each dilution.If that is enough to perform all of your tests, this dilution planwill work. If you need larger volumes, increase the volumes you useto make your dilutions (e.g. 2.0 ml + 2.0 ml in each step).
SummarySolutions are utilized to some degree in almost all biological research applications. Therefore understanding how to measure and manipulate them is imperative to any experiment.
In this video, concepts in preparing solutions are introduced.Solutions consist of a solute dissolved in solvent to yield a homogeneous mixture of molecular substances. Solutions are generally identified by their components and corresponding concentrations. Concentrated solutions are diluted through various methods, such as serial dilution.This video also lays a foundation for the accurate preparation of solutions.
For example, the video reviews how to measure volumes with precision through use of the appropriate volumetric container as well as how to read the volume when a meniscus is present.Some applications for measuring volumes are then presented. Gel electrophoresis is a commonly used laboratory procedure which requires preparation of a percent weight volume solution as well as parallel dilution of a concentrated stock solution.
Use of a serial dilution to prepare standards for generating a standard curve in protein quantitation is also demonstrated. When performing experiments, it is imperative to know the exact concentration of solutions used.Concentration is most commonly expressed as molarity.
A one molar solution contains one mol of solute per liter of solution (B+C). When making solutions in the lab, the mols of solute can be determined from the measured mass of the molecule and its molecular weight.Solutions can also be prepared and quantified as percent concentrations from the weight of solute per unit volume of solvent, known as a percent weight-volume solution.Keep in mind that the solute is sometimes in liquid form. In this case, the percent concentration can be expressed as the volume of liquid solute per unit volume of solvent, referred to as a percent volume-volume solution.For frequent use, concentrated solutions of stable compounds, known as stock solutions, can be prepared.
Stock solutions may be labeled as a multiple of the concentration in the final working solution. Here you see a 10X solution.These stock solutions can be diluted as necessary with solvent to achieve the desired concentration.Alternatively, a dilution can be prepared from a more concentrated solution using a parallel dilution. Using this simple calculation, a solution of desired concentration and desired volume can be prepared from a stock solution of known concentration.
Serial Vs Parallel Dilution Method Definition
The resulting volume can be diluted to the total volume of the solution to achieve the desired concentration.However, in some situations, the dilution factor, which is equal to the final volume divided by volume of stock solution needed for the dilution, is too large. This makes parallel dilution impractical as the necessary volume of the stock solution would be too small to accurately measure.With the serial dilution technique, a stock solution can be used to make a dilute solution, which can then be diluted further to make a more dilute solution and so on until the desired concentration is met. When measuring volumes in the lab you will come across many containers that can hold liquid. However, it is important to realize that not all of these vessels are designed for accurately measuring volume.Non-volumetric containers, such as beakers and Erlenmeyer flasks, are designed for mixing and storing solutions and are generally not calibrated.
Instead, the measurements, or graduations, on the side represent approximations of liquid capacity.Conversely, volumetric labware is designed to measure exact volumes of liquid substances. Volumetric labware is denoted with the capacity it is calibrated to hold as well as the letters TC or TD.TC stands for “to contain” and is generally found on volumetric flasks and graduated cylinders, which are calibrated to hold a precise volume of liquid.TD denotes “to deliver” and is usually found on measuring devices designed to dispense liquid, such as pipettes and syringes.Volumetric flasks are generally used to prepare solutions of a specific concentration. After dissolving the solute, solvent is added to the flask until the total volume reaches the graduation line. Adding the “quantity sufficient” to reach this volume is known as Q.S.’ing the solution.When Q.S.’ing the solution, the top of the liquid curves where it meets the flask.
Serial Vs Parallel Dilution Method
This is called the meniscus and is caused by surface tension. In an aqueous solution, the meniscus is concave, and should be read at the lowest point of the curve.There are several vessels designed to measure and deliver specific volumes of liquid. When choosing volumetric labware, always select the smallest device that will accommodate the desired volume to achieve the highest accuracy.When measuring volumes of liquid above 50 mL, graduated cylinders are the appropriate choice.Serological pipettes are generally used to measure and deliver volumes in the range of 0.1 to 50 mL.For volumes of 0.2 microliters to 5 mL, micropipettors should be used.When plastic pipette tips are not compatible with the liquid to be measured, glass Hamilton syringes are an alternative for accurate measurement of volumes in the microliter range.
Serial Vs Parallel Wiring
Now that we have covered the basics of working with solutions, we’ll discuss how some of these concepts are applied in research.DNA Gel electrophoresis is a technique used to separate a mixed population of DNA fragments, to estimate their size, by applying an electric field to move the negatively charged molecules through a gel matrix made of agarose – a carbohydrate from seaweedIn preparing the gel matrix, percent weight/volume solutions are commonly used to make 1% weight/volume agarose gels.Generally electrophoresis requires large quantities of running buffers. You’ve just watched JoVE’s introduction to understanding concentration and measuring volumes. In this video we reviewed some basic concepts such as calculating concentration, performing dilutions, and how different types of labware are used to measure volumes. Applications of some of the concepts introduced in this video were also discussed for molecular biology and biochemistry.Thanks for watching and remember to always use accuracy and precision when measuring volumes.A subscription to J oVE is required to view this content. You will only be able to see the first 20 seconds.