April 25, 2005 - BLAST programs

When I run BLASTP, BLASTX, or TBLASTX I get an error message that says, "Unable to open BLOSUM62." What do I need to do?

The BLAST programs that do comparisons on a protein-protein basis use scoring matrices to evaluate matches. In order for the programs to find them, you need to place a file called .ncbirc in your home directory that contains the path to the matrices.

• Use a text editor, such as pico, to create a file in your home directory that is named .ncbirc ("dot" ncbirc) and that has the following contents:
  
  

   [NCBI] 

  Data=/bioportal/sw/share/blast/data/