Depth of Coverage

Question

[Fatemeh Nabizadeh]

Hello

I am dealing with the whole exome data, and want to filter out the variants whose depth of coverage for alt divided to ref allele (alt/ref) is less than or equal to 30%.

This is what the .tsv file looks like:

chr1    45797228        45797228        C       T       PASS    het   68      13.77   60.00   99   68      944,0,1119      **37,31**    1       exonic ...............................

Column 14 ("37,31") is the column of my interest.

37: depth of coverage for ref allele, 
31: depth of coverage for alt allele

Would you please help me with how to do that? I'm working with Linux, and need something like an awk command.