Presentation on theme: "Dot Plot. Goal We will take two nucleotide base strings and look for common patterns – stretches where the bases match. GAATTCATACCAGATCACCGAAAACTGTCCTCCAA."— Presentation transcript:
Goal We will take two nucleotide base strings and look for common patterns – stretches where the bases match. GAATTCATACCAGATCACCGAAAACTGTCCTCCAA ATGTGTCCCCCTCACACTCCCAAAT TCGCGGGCTTCTGCTCTTAGACCACTCTACCCTAT TCCCCACACTCACCGGAGCCAAAGC
Start by entering the two sequences in question in Excel
Use the LEN Function to determine the length of the string
Set up a grid – mine was 60-by-60 since the lengths were 60
Enter the length of match one is seeking – start with 1
Anatomy of the formula (Part 1) =IF(MID($B$1,E$3,$B$4)=MID($B$2,$D4,$B$4),1,0) Recall MID takes a string $B$1 is the first base sequence and $B$2 is the second base sequence Then MID takes a part of the string beginning at the “second argument”
Anatomy of the formula (Part 2) =IF(MID($B$1,E$3,$B$4)=MID($B$2,$D4,$B$4),1,0) The starting point varies. E$3 stays in the third row as the formula is copied and uses the various numbers 1 through 60 set up in row 3. $D4 stays in column D and uses the various numbers 1 through 60 set up in column D.
Anatomy of the formula (Part 3) The third argument is the length of the match we seek. They are both the same length. If the two “substrings” (base mini sequences) match, output a 1, otherwise a zero. Then copy the formula throughout the grid.
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