Expectation value (Evalue)
1
0
Entering edit mode
7.9 years ago
itsanju87 ▴ 10

I have set evalue in BLASTX as 1e-10, I got hits with evalues 2e-39, 3e-40,8e-34. Are these evalues higher/lower than the specified evalue? Should i consider sequences with these new evalues as protein coding?

blast • 1.3k views
ADD COMMENT
0
Entering edit mode

What do you think? This should provide a clue.

ADD REPLY
3
Entering edit mode
7.9 years ago

Evalue of 1e-10 equals to 0.0000000001. This value describes the number of hits you can "expect" to see by chance when searching a database of a particular size. It decreases exponentially as the score of the match increases. For example, an E value of 1 assigned to a hit can be interpreted as meaning that in a database of the current size one might expect to see 1 match with a similar score simply by chance.

Therefore, the lower the E-value, or the closer it is to zero, the more statistically significant the match is. The E-values you have there are very low and thus you should consider these sequences as putative proteins.

ADD COMMENT

Login before adding your answer.

Traffic: 1906 users visited in the last hour
Help About
FAQ
Access RSS
API
Stats

Use of this site constitutes acceptance of our User Agreement and Privacy Policy.

Powered by the version 2.3.6