Discrepancy in number of BLAST hits

Question

[georgeyates1994]

Hi all,

I was just wondering if anyone here could shed light on a discrepancy I've noticed when retrieving and viewing blast results from NCBI.

The NCBI BLAST results page is displaying '243 results' - however, when I select all and download as an alignment hit table (CSV) and a FASTA of all the aligned sequences, I'm finding about a hundred additional entries appear in my exported results.

Does anyone know where these might be generated from?

Answer 1

[lakhujanivijay]

That should not be a discrepancy. Those hundred additional entries reported for each hit are high-scoring segment pairs (HSPs)

[georgeyates1994]

Ah, that makes things clearer - thanks for the help.