11
Introduction to Sequence Analysis
Nucleotide Analysis
Interpreting the results of BLAST2 EVEC
¥ Click the button ÒBLAST resultÓ to see the results
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¥ You should have noticed that sequence 1 and sequence 2 appear to be contaminated with vectors
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¥ A closer look is required to see if these are genuine hits, or a result of finding a loose match to a similar functional domain to one found in the vectors database. This is due to the contents of the database, and the e-values allowing these hits to pass through
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¥ In the case of sequence 1, you will see that the parameter ÒValueÓ for all these hits is zero, so all these hits are exact matches and are definitly a result of vector contamination (no gaps in the alignment)
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¥ In the case of sequence 2, you will see that the parameter ÒValueÓ for all these hits is always positive. As a rule of thumb, for a first look at these, if the value is not Òto the power ofÓ (e.g. 1.2x10-7) it is not likely to be significant
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