1. Standard Curve Analysis for DNA Quantitation
Writing Lab Report 1
Standard Curve Analysis for DNA Quantitation

2. Conclusion identifying the relationships observed in the data analysis
Contents of Lab Report 1
Cover Page
Results
Text
Two Figures (graphs) with proper captions
One Table with a proper caption
Discussion
For each figure and table provide a(n)
Data Analysis
Error Analysis
Conclusion identifying the relationships observed in the data analysis

3. Cover Page
Your name
Names of your lab partners
Lab Section
Date

4. Results: Text Briefly describe what each figure and table represents
introduce the reader to the order in which you are presenting the data
use an objective description that explains what you expect the reader to notice about the data
do not interpret the data in this section
do not provide error analysis
You 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 1
Use Excel to plot the absorbance values at each concentration for YOUR GROUP’S data
Superimpose a smooth trendline
Record the equation of the trendline to present in the caption and use in calculations for Table 1
Label 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 include
source of the data
relationship observed, including equation for trendline
how 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 2
For CLASS DATA, use Excel to plot the mean values for absorbance at each concentration
Superimpose a smooth trendline (reporting the equation for this trendline is optional)
Use the standard deviation values for Vertical (Y) error bars
Label the axes appropriately, indicating the x and y variables and their units of measure
Provide a caption below the figure, including
Title
Brief 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 1
Determine 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 instructions
Use any table format that clearly shows the results
Showing the calculations is optional
Provide a caption above the table, including
Title
Brief 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)3 4 5 6 7
Weight (g)
Abs550 for Methylene Blue-stained DNA solution
Concentration of Solution (%) (from standard curve)
Concentration of DNA (micrograms/mL)
Total Amount of DNA Recovered (micrograms)
DNA Yield (micrograms DNA/gram strawberry) 25
Absorbance reading for 5 mL solution containing methylene blue-stained DNA from one strawberry DNA extraction
1.1

15. Using the Standard Curve in Figure 1 to determine the percentage of methylene blue corresponding to the DNA solution
Substitute 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)3 4 5 6 7
Weight (g)
Abs550 for Methylene Blue-stained DNA solution
Concentration of Solution (%) (from group’s standard curve)
Concentration of DNA (micrograms/mL)
Total Amount of DNA Recovered (micrograms)
DNA Yield (micrograms DNA/gram strawberry) 25
For Column 5: Use conversion factor shown below: % = % Z = micrograms/milliliter
0.086 micrograms/milliliter Z
0.70
For Column 7: Divide by the starting weight of the strawberry micrograms/25 grams = 0.14 micrograms DNA/grams strawberry
0.14
1.1
For Column 6: Correct for 5 ml total volume micrograms/milliliter x 5 milliliters = 3.5 micrograms
3.5
0.008

17. Discussion: Data Analysis
See Lab Manual Instructions for specific questions to consider in analyzing the data
For 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 BRIEF
Suggest sources that match both the direction and magnitude of the error
If 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) error
Indicate which sources of error are specific to each figure/table presented

20. Conclusion
Write one (or a few) brief statement(s) that summarizes the relationship(s) observed between the variables that you studied
Comment on the variation observed for the class data

21. Collaboration
You may DISCUSS any aspects of your lab report with fellow students and/or your instructor
You must PRODUCE the figures and WRITE your lab report independently
Any 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.