Presentation on theme: "Standard Curve Analysis for DNA Quantitation"— Presentation transcript:
1 Standard Curve Analysis for DNA Quantitation Writing Lab Report 1Standard Curve Analysis for DNA Quantitation
2 Conclusion identifying the relationships observed in the data analysis Contents of Lab Report 1Cover PageResultsTextTwo Figures (graphs) with proper captionsOne Table with a proper captionDiscussionFor each figure and table provide a(n)Data AnalysisError AnalysisConclusion identifying the relationships observed in the data analysis
3 Cover PageYour nameNames of your lab partnersLab SectionDate
4 Results: Text Briefly describe what each figure and table represents introduce the reader to the order in which you are presenting the datause an objective description that explains what you expect the reader to notice about the datado not interpret the data in this sectiondo not provide error analysisYou may briefly explain the pattern observed in the data and/or refer to the relationship indicated by the shape of each graph. Use the descriptions in the Lab Manual section “How to Write a Scientific Report” pages
5 Results: Figure 1Use Excel to plot the absorbance values at each concentration for YOUR GROUP’S dataSuperimpose a smooth trendlineRecord the equation of the trendline to present in the caption and use in calculations for Table 1Label the axes appropriately, indicating the x and y variables and their units of measure
6 Also for Figure 1 Provide a caption below the figure title brief description, that can includesource of the datarelationship observed, including equation for trendlinehow the figure will be used in the results and/or discussion sections
7 Example of Figure 1 with Dr. Colavito’s Data Obtained in Summer 2010
8 Example of Figure 1 with Data Obtained in Summer 2010 Adding a Trendline Be sure to copy the trendline equation and save it to use later. For the line on this grapy: y = x ; R2 =
9 Example of Figure 1 with Data Obtained in Summer 2010 Adding a Caption I am the title of this PowerPoint slide, not the title of the graph. Do not copy my format in your lab report!I am the description for this figure caption. Yours will be more specific to the experiment you performed, of course.I am the title for this figure. Follow my format but use your own words.Figure 1: Standard Curve of Methylene Blue Absorbance. Absorbance values were obtained for dilutions of a 0.01% methylene blue solution. The equation for the trendline is y = x ; R2 =
10 Results: Figure 2For CLASS DATA, use Excel to plot the mean values for absorbance at each concentrationSuperimpose a smooth trendline (reporting the equation for this trendline is optional)Use the standard deviation values for Vertical (Y) error barsLabel the axes appropriately, indicating the x and y variables and their units of measureProvide a caption below the figure, includingTitleBrief description
11 Example of Figure 2 with Data Obtained in Summer 2010
12 Example of Figure 2 with Data Obtained in Summer 2010 Adding Error Bars Each error bar shows the range of +1SD from the mean value.
13 Results: Table 1Determine the total yield of YOUR DNA EXTRACTION and show the process by providing the information for Columns 2-7 from Table 2 in the lab instructionsUse any table format that clearly shows the resultsShowing the calculations is optionalProvide a caption above the table, includingTitleBrief Description: This description should include the calculated value of the mean + 1 standard deviation for DNA Yield, using the class data.
14 Data to present in Table 1 (taken from Table 2 of Lab Instructions) 34567Weight (g)Abs550 for Methylene Blue-stained DNA solutionConcentration of Solution (%) (from standard curve)Concentration of DNA (micrograms/mL)Total Amount of DNA Recovered (micrograms)DNA Yield (micrograms DNA/gram strawberry)25Absorbance reading for 5 mL solution containing methylene blue-stained DNA from one strawberry DNA extraction1.1
15 Using the Standard Curve in Figure 1 to determine the percentage of methylene blue corresponding to the DNA solutionSubstitute 1.1 for the y value in the trendline equation: y = x ; x=0.0081%
16 Data to present in Table 1 (taken from Table 2 of Lab Instructions) 34567Weight (g)Abs550 for Methylene Blue-stained DNA solutionConcentration of Solution (%) (from group’s standard curve)Concentration of DNA (micrograms/mL)Total Amount of DNA Recovered (micrograms)DNA Yield (micrograms DNA/gram strawberry)25For Column 5: Use conversion factor shown below: % = % Z = micrograms/milliliter0.086 micrograms/milliliter Z0.70For Column 7: Divide by the starting weight of the strawberry micrograms/25 grams = 0.14 micrograms DNA/grams strawberry0.141.1For Column 6: Correct for 5 ml total volume micrograms/milliliter x 5 milliliters = 3.5 micrograms3.50.008
17 Discussion: Data Analysis See Lab Manual Instructions for specific questions to consider in analyzing the dataFor Figure 1, state the line/curve shape that you proposed and then explain WHY the line/curve would be this shape. Be sure to consider the mathematical relationship illustrated by the line/curve shape. Your goal is to address the MECHANISM by which this relationship occurs.For Figure 2, discuss how well the data fit the proposed line/curve. Does the range shown by the data points + error bars overlap the best fit line? If your data fit the proposed line/curve shape, TENTATIVELY accept the mechanism as an explanation for the observed relationship.
18 Discussion: Data Analysis For Table 1, consider the usefulness of the standard curve in quantifying the DNA extracted from strawberries. Address the specificity of the protocol in isolating DNA. Describe whether your individual DNA yield is reasonable in comparison to the class data.
19 Discussion: Error Analysis Be BRIEFSuggest sources that match both the direction and magnitude of the errorIf deviation of data points from the curve or line is not large, do NOT suggest major sources of error.At least two sources of error should be identified, one should be systematic error, the other should be intrinsic (random) errorIndicate which sources of error are specific to each figure/table presented
20 ConclusionWrite one (or a few) brief statement(s) that summarizes the relationship(s) observed between the variables that you studiedComment on the variation observed for the class data
21 CollaborationYou may DISCUSS any aspects of your lab report with fellow students and/or your instructorYou must PRODUCE the figures and WRITE your lab report independentlyAny unusual similarities will be addressed according to the SMC Code of Academic Conduct. Everyone involved will lose full credit for their reports. There are no makeups for lab reports showing academic dishonesty.