Ckaplan Week 9

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Purpose:

We're utilizing Excel to practice loading data and conducting statistical analysis specifically on the gene expression data of the "Δgln3" strain. This exercise helps us refine our skills in organizing interpreting biological data.

Methods:

We are analyzing Δgln3 data.

-filename: BIOL367_S24_microarray-data_dGLN3CKAS312.xlsx

Media:BIOL367_S24_microarray-data_dGLN3CKAS312.xlsx.

Media:BIOL367_S24_microarray-data_dGLN3CKAS3121.xlsx.

Procedure:

  • Creating a New Worksheet: I created a new worksheet named "Δgln3_ANOVA" to conduct the ANOVA analysis for the strain "Δgln3".
  • Copying Data: I copied all the data from the "Master_Sheet" worksheet and pasted it into the new "Δgln3_ANOVA" worksheet.
  • Adding Column Headers: I added five column headers to the right of the data, named "Δgln3_AvgLogFC_15", "Δgln3_AvgLogFC_30", "Δgln3_AvgLogFC_60", "Δgln3_AvgLogFC_90", and "Δgln3_AvgLogFC_120".
  • Calculating Average Log Fold Change: I used the AVERAGE function to calculate the average log fold change for each timepoint. For example, in cell B2, I typed "=AVERAGE(C2:G2)" to calculate the average log fold change at t=15 minutes for the first gene, and then I double-clicked the fill handle to copy the formula for all genes.
  • Calculating Sum of Squares (SS): In the "Δgln3_ss_HO" column, I used the SUMSQ function to calculate the sum of squares for each timepoint.
  • Calculating Total SS: In the "Δgln3_SS_full" column, I summed the SS values for each timepoint to get the total SS.
  • Calculating F-statistic: Using the formula provided, I calculated the F-statistic for each gene by replacing placeholders with the appropriate cell references.
  • Calculating p-value: I used the FDIST function to calculate the p-value for each gene based on the F-statistic and the degrees of freedom.
  • Performing Sanity Check: I applied a filter to the p-value column to display only values less than 0.05 to verify the results.
  • Calculating Bonferroni-corrected p-value: I created a new column for Bonferroni-corrected p-values and applied the correction formula, replacing any values greater than 1 with 1.
  • Calculating Benjamini & Hochberg p-value Correction:

I inserted a new worksheet named "Δgln3_ANOVA_B-H". I copied the relevant columns from the ANOVA worksheet and pasted them into the new worksheet. I sorted the data by ascending p-values and added a rank column from 1 to 6189. I calculated the B-H p-value correction using the provided formula. I corrected B-H p-values greater than 1 to 1. I sorted the data back by MasterIndex and copied corrected p-values to the ANOVA worksheet.


Assignment Pages

Individual Journal Entry Pages

Shared Journal Entry Pages