how to determine a fastq is phred+33 or phred+64

Question

[Pei]

Hello everyone!

here is a simple question: If I got a fastq from public database, is it possible to determine whether its quality score is phred + 33 or phred + 64 based on the file itself?

Thanks!

Pei

[cpad0112]

In Phred 64 files, you should not be seeing phred values <64. But you can also look at upper case and lower case of quality representations (ascii letters). In general, lower case means 64.

[Pei]

Thanks! I'll check that.

Answer 1

[Mensur Dlakic]

There are many ways of doing it - see here.

[Pei]

Thanks!

I'll check these.