extending reads in ChIP-Seq analysis

[frymor]

Hi,

we're working on a ChIP-Seq data set. I have read in some tutorials and workflows that after mapping the reads, they should be extended to the estimated fragment size.

Am I correct in the assumption that this is done, so that the estimation of read counts covers not only the sequenced read(s), but the complete IP-ed fragment.

Should this be done for every ChIP-Seq analysis, irrespectively whether it is single-end or paired-end, or any other sequencing parameters?

thanks,
Assa