2. The dilution factor is the inverse of the concentration factor. Prepare 40 mL of 5.0 µg/mL Methylene Blue Working Solution, Prepare 80% Methylene Blue Working Solution, Prepare 60% Methylene Blue Working Solution, Prepare 40% Methylene Blue Working Solution, Prepare 20% Methylene Blue Working Solution, Complete Data Table 1. based on your results. You have a concentrated antibody solution, so you make a 5 -fold dilution and measure at 280 n m, getting an absorbance of 0.845. Pipette 5.0 mL of DI water into the tube for a total of 10 mL of solution. Figure 1. % drug release= [Amount released in step 2 x 100] / … It is common for solutions that are used often in a lab (or which are time consuming to prepare) to be intentionally prepared to be many times more concentrated than needed. Place the blank into the spectrophotometer. Samples yielding OD values below or above the standard range should be re-analyzed at appropriate dilutions. However, the spectrophotometer can only measure absorbance up to 4.5 directly. Place 1 mL of DI water into a clean cuvette. Transfer all of the solution back into your 50 mL conical tube and secure the cap. Make sure to include steps to verify your solution by checking the pH. Relevance. For example, if you take 1 part of a sample and add 9 parts of water (solvent), then you have made a 1:10 dilution; this has a concentration of 1/10th (0.1) of the original and a dilution factor of 10. Dilution factor is defined as: total volume of solution per aliquot volume. You can obtain the values for the variables in the algebraic equation by using spectrophotometry. Pipette 6.0 mL of 5.0 µg/mL methylene blue working solution into a 15 mL conical tube. Describe how you would prepare 50.0-mL a 0.10% NaOH solution. Using Beer's Law this is my work: 0.845 = (1.4) ⋅ (1) ⋅ (c) ∴ c = 0.604 m o l L − 1 How many grams of dry NaCl should be used to make 300 mL of 6% (W/V) NaCl solution? For example, if you take 1 part of a sample and add 9 parts of water (solvent), then you have made a 1:10 dilution; this has a concentration of 1/10th (0.1) of the original and a dilution factor of 10. Then, rearrange the Beer-Lambert equation into an algebraic equation so you can solve for molar absorptivity. Where total volume of solution is: 10.0 + 240.0 = 250.0 mL (volumetric flask.) The concentration factor is the initial volume divided by the final solution volume. On the Insert tab, click on the Scatter icon and select Scatter with Straight Lines and Markers from its drop-down menu to generate the standard curve. If you have a standard curve available you … Calculate how to prepare 150 mL 1.8 % (w/v) agarose in 1X SB buffer, given dry agarose and SB buffer. Draw a best fit curve through the points in the graph (we suggest that a suitable … Dilution Factor Undiluted Lake … Describe how you would prepare 100.0 mL of 1X sodium acetate solution from the 10x sodium acetate solution prepared in the questions above. This will provide enough data for statistical validation of the results. unit is ug/mL. In your description, include a calculation and step by step procedures including glassware. Duplicates should be within 20% of the mean. 2. Standard curve Create a standard curve for the target protein by plotting the mean absorbance (x axis) against the protein concentration (y axis). Pipette 2.0 mL of 5.0 µg/mL methylene blue working solution into a 15 mL conical tube. Use the spectrophotometer to measure the absorbance of a solution. Label the bottle with the solution with the following information: The name of the solution (include concentrations), Write a fraction for the concentration \[5\:\%\: ( \frac{w}{v} )\: =\: \dfrac{5\: g\: sucrose}{100\: mL\: solution} \nonumber\], Set up a proportion \[\dfrac{5\: g\: sucrose}{100\: mL\: solution} \:=\: \dfrac{?\: g\: sucrose}{500\: mL\: solution} \nonumber\], Solve for g sucrose \[\dfrac{5\: g\: sucrose}{100\: mL\: solution} \: \times \: 500 \: mL \: solution \: = \: 25 \: g \: sucrose \nonumber\]. If initial absorbance measurements exceed 2.0, dilute the sample, or an aliquot thereof, by a factor necessary to obtain absorbance values less than 2.0. Calculate the amount of sodium acetate needed to make 30 mL of 13.6% sodium acetate solution. Using the remainder of your 5.0 µg/mL methylene blue working solution from part 2, perform a set of 1:2 serial dilutions to make the following concentrations of the solution (50.0 %, 25.0 %, 12.5 %, 6.25 %, 3.125 %, and 1.5625 %). To add a trendline to the graph, right-click on the standard curve line in the chart to display a pop-up menu of plot-related actions. Your accuracy can be verified by taking a pH reading. The slope and the y-intercept are provided to you when the computer fits a line to your standard curve data. Review of Dilution, Concentration, and Stock Solutions . A serial dilution is a series of stepwise dilutions, where the dilution factor is held constant at each step. Setting up the equation with this data y... Snapchat will now trust this device until you choose to forget it.