hg18 or hg19

[Layla]

Does anybody know the difference between the following files for Bowtie?
File: h_sapiens_37_asm.ebwt.zip (27-08-09) and
File: h_sapiens_asm.ebwt.zip (18-02-09)
Files found from:
http://bowtie-bio.sourceforge.net/md5s.shtml

Is it a difference in the genomes or something else?
I want to be using hg18 version of the genome

Cheers

L

[simonandrews]

If you look at the 'pre-built indexes' panel on the right of that page you can see what the different files are.

The h_sapiens_37 comes from the new GRCh37 assembly from earlier this year. The h_sapiens_asm is the older NCBI36 assembly, which would correspond to hg18.