@RG ( read group ) in neandertals

Question

[khatami.mahshid]

I have some bam files from Neandertals I downloaded from UCSC. I want to first merge them and then convert to VCF file. but when I search for @RG in bam files to see if they are from the same library, it shows they don't have @RG. I use this command to find @RG in bam files:

samtools view -H SLFeld1.hg19.bam | grep "^@RG" > RG_SLFeld

why these bam files don't have @RG?

thanks a lot

Answer 1

[WouterDeCoster]

Because it is not required. You can set or change a read group using samtools addreplacerg, or with Picard and probably others too.