Writing Lab Report 1Writing Lab Report 1

Standard Curve Analysis Standard Curve Analysis for DNA Quantitationfor DNA Quantitation

Contents of Lab Report 1Contents of Lab Report 1

Cover PageCover Page ResultsResults

TextTextTwo Figures (graphs) with proper captionsTwo Figures (graphs) with proper captionsOne Table with a proper captionOne Table with a proper caption

DiscussionDiscussionFor each figure and table provide a(n) For each figure and table provide a(n)

Data AnalysisData AnalysisError AnalysisError Analysis

Conclusion identifying the relationships Conclusion identifying the relationships observed in the data analysisobserved in the data analysis

Cover PageCover Page

Your name Your name Names of your lab partnersNames of your lab partnersLab SectionLab SectionDateDate

Results: TextResults: Text

Briefly describe what each figure and table Briefly describe what each figure and table representsrepresents introduce the reader to the order in which you are introduce the reader to the order in which you are

presenting the datapresenting the data use an objective description that explains what you use an objective description that explains what you

expect the reader to notice about the dataexpect the reader to notice about the data do not interpret the data in this section do not interpret the data in this section do not provide error analysisdo not provide error analysis

You may briefly explain the pattern observed You may briefly explain the pattern observed in the data and/or refer to the relationship in the data and/or refer to the relationship indicated by the shape of each graph. Use the indicated by the shape of each graph. Use the descriptions in the Lab Manual section “How descriptions in the Lab Manual section “How to Write a Scientific Report” pages 11-12. to Write a Scientific Report” pages 11-12.

Results: Figure 1Results: Figure 1

Use Excel to plot the absorbance values at each Use Excel to plot the absorbance values at each concentration for YOUR GROUP’S dataconcentration for YOUR GROUP’S data

Superimpose a smooth trendline Superimpose a smooth trendline Record the equation of the trendline to present Record the equation of the trendline to present

in the caption and use in calculations for Table 1in the caption and use in calculations for Table 1 Label the axes appropriately, indicating the x Label the axes appropriately, indicating the x

and y variables and their units of measureand y variables and their units of measure

Also for Figure 1Also for Figure 1

Provide a caption Provide a caption below the figurebelow the figuretitle title brief description, that can includebrief description, that can include

source of the datasource of the datarelationship observed, including relationship observed, including

equation for trendlineequation for trendlinehow the figure will be used in the how the figure will be used in the

results and/or discussion sectionsresults and/or discussion sections

Example of Figure 1 with Dr. Colavito’s Data Obtained in Summer 2010

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Example of Figure 1 with Data Obtained in Summer 2010Adding a Trendline

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Be sure to copy the trendline equation and save it to use later.For the line on this grapy: y = 145.52x - 0.0793; R2 = 0.9849.

Example of Figure 1 with Data Obtained in Summer 2010Adding a Caption

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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 title for this figure. Follow my

format but use your own words.

I am the description for this figure caption.

Yours will be more specific to the

experiment you performed, of course.

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 = 145.52x - 0.0793; R2 = 0.9849.

Results: Figure 2Results: Figure 2

For CLASS DATA, use Excel to plot the mean For CLASS DATA, use Excel to plot the mean values for absorbance at each concentration values for absorbance at each concentration

Superimpose a smooth trendlineSuperimpose a smooth trendline(reporting the equation for this trendline is optional)(reporting the equation for this trendline is optional)

Use the standard deviation values for Vertical Use the standard deviation values for Vertical (Y) error bars(Y) error bars

Label the axes appropriately, indicating the x Label the axes appropriately, indicating the x and y variables and their units of measureand y variables and their units of measure

Provide a caption Provide a caption below the figure, below the figure, includingincludingTitleTitleBrief descriptionBrief description

Example of Figure 2 with Data Obtained in Summer 2010

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Example of Figure 2 with Data Obtained in Summer 2010Adding Error Bars

Each error bar shows the range of +1SD from the mean value.

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Results: Table 1Results: Table 1

Determine the total yield of YOUR DNA Determine the total yield of YOUR DNA EXTRACTION and show the process by providing the EXTRACTION and show the process by providing the information for Columns information for Columns 2-7 from Table 2 in the lab instructions2-7 from Table 2 in the lab instructions

Use any table format that clearly shows the results Use any table format that clearly shows the results Showing the calculations is optionalShowing the calculations is optional Provide a caption Provide a caption above the table,above the table, including including

TitleTitle Brief Description: This description should include Brief Description: This description should include

the calculated value of the mean the calculated value of the mean ++ 1 standard 1 standard deviation for DNA Yield, using the class data. deviation for DNA Yield, using the class data.

Data to present in Table 1Data to present in Table 1(taken from Table 2 of Lab Instructions)(taken from Table 2 of Lab Instructions)

Absorbance reading for 5 mL solution

containing methylene blue-stained DNA

from one strawberry DNA extraction

1.11.1

22 33 44 55 66 77

Weight Weight (g)(g)

AbsAbs550 550 for for

Methylene Methylene Blue-stained Blue-stained

DNA solution DNA solution

Concentration Concentration of Solution (%)of Solution (%)(from standard (from standard

curve) curve)

Concentration of Concentration of DNA DNA

(micrograms/mL)(micrograms/mL)

Total Amount of Total Amount of DNA RecoveredDNA Recovered(micrograms) (micrograms)

DNA Yield DNA Yield (micrograms (micrograms DNA/gram DNA/gram

strawberry) strawberry)

2525

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 = 145.52x - 0.0793; x=0.0081%

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Concentration of Methylene Blue (%)

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Data to present in Table 1Data to present in Table 1(taken from Table 2 of Lab Instructions)(taken from Table 2 of Lab Instructions)

22 33 44 55 66 77

Weight Weight (g)(g)

AbsAbs550 550 for for

Methylene Methylene Blue-stained Blue-stained

DNA solution DNA solution

Concentration Concentration of Solution (%)of Solution (%)(from group’s (from group’s

standard curve) standard curve)

Concentration of Concentration of DNA DNA

(micrograms/mL)(micrograms/mL)

Total Amount of Total Amount of DNA RecoveredDNA Recovered(micrograms) (micrograms)

DNA Yield DNA Yield (micrograms (micrograms DNA/gram DNA/gram

strawberry) strawberry)

For Column 5: Use conversion factor shown below:For Column 5: Use conversion factor shown below:0.001%0.001% = = 0.0081%0.0081% Z = 0.70 micrograms/milliliter Z = 0.70 micrograms/milliliter0.086 micrograms/milliliter0.086 micrograms/milliliter Z Z

0.700.70

For Column 6: Correct for 5 ml total volume. For Column 6: Correct for 5 ml total volume. 0.70 micrograms/milliliter x 5 milliliters = 3.5 micrograms 0.70 micrograms/milliliter x 5 milliliters = 3.5 micrograms

3.53.5

For Column 7: Divide by the starting weight of the strawberry. For Column 7: Divide by the starting weight of the strawberry. 3.5 micrograms/25 grams = 0.14 micrograms DNA/grams strawberry 3.5 micrograms/25 grams = 0.14 micrograms DNA/grams strawberry

0.140.142525 1.11.1 0.0080.008

Discussion: Data AnalysisDiscussion: Data Analysis

See Lab Manual Instructions for specific See Lab Manual Instructions for specific questions to consider in analyzing the dataquestions to consider in analyzing the data

For Figure 1, state the line/curve shape that you For Figure 1, state the line/curve shape that you proposed and then explain WHY the line/curve proposed and then explain WHY the line/curve would be this shape. Be sure to consider the would be this shape. Be sure to consider the mathematical relationship illustrated by the mathematical relationship illustrated by the line/curve shape. Your goal is to address the line/curve shape. Your goal is to address the MECHANISM by which this relationship occurs.MECHANISM by which this relationship occurs.

For Figure 2, discuss how well the data fit the For Figure 2, discuss how well the data fit the proposed line/curve. Does the range shown by proposed line/curve. Does the range shown by the data points the data points ++ error bars overlap the best fit error bars overlap the best fit line? If your data fit the proposed line/curve line? If your data fit the proposed line/curve shape, TENTATIVELY accept the mechanism as shape, TENTATIVELY accept the mechanism as an explanation for the observed relationship.an explanation for the observed relationship.

Discussion: Data AnalysisDiscussion: Data Analysis

For Table 1, consider the usefulness of the For Table 1, consider the usefulness of the standard curve in quantifying the DNA standard curve in quantifying the DNA extracted from strawberries. Address the extracted from strawberries. Address the specificity of the protocol in isolating DNA. specificity of the protocol in isolating DNA. Describe whether your individual DNA yield Describe whether your individual DNA yield is reasonable in comparison to the class is reasonable in comparison to the class data. data.

Discussion: Error AnalysisDiscussion: Error Analysis

Be BRIEFBe BRIEF Suggest sources that match both the direction Suggest sources that match both the direction

and magnitude of the errorand magnitude of the error If deviation of data points from the curve or line is If deviation of data points from the curve or line is

not large, do NOT suggest major sources of error.not large, do NOT suggest major sources of error. At least two sources of error should be At least two sources of error should be

identified, one should be systematic error, the identified, one should be systematic error, the other should be intrinsic (random) errorother should be intrinsic (random) error

Indicate which sources of error are specific to Indicate which sources of error are specific to each figure/table presentedeach figure/table presented

ConclusionConclusion

Write one (or a few) brief statement(s) Write one (or a few) brief statement(s) that summarizes the relationship(s) that summarizes the relationship(s) observed between the variables that you observed between the variables that you studiedstudied

Comment on the variation observed for Comment on the variation observed for the class datathe class data

CollaborationCollaboration

You may DISCUSS any aspects of your lab You may DISCUSS any aspects of your lab report with fellow students and/or your report with fellow students and/or your instructorinstructor

You must PRODUCE the figures and WRITE You must PRODUCE the figures and WRITE your lab report independently your lab report independently

Any unusual similarities will be addressed Any unusual similarities will be addressed according to the SMC Code of Academic according to the SMC Code of Academic Conduct. Everyone involved will lose full credit Conduct. Everyone involved will lose full credit for their reports. There are no makeups for lab for their reports. There are no makeups for lab reports showing academic dishonesty. reports showing academic dishonesty.