Sequence trimming
In the "Sequence trimming" wizard step (figure 29.13), a fixed number of bases can be removed from either or both ends of reads, or reads can be trimmed to a specified length.
Figure 29.13: Sequence trimming.
Removing a fixed number of bases
Separate options are available for removing a fixed number of bases from the 5' end or from the 3' end.
At least one of the options Remove on first read or Remove on second read (for paired reads) must be checked. If neither are checked, reads are not trimmed.
Trimming reads to a fixed length
The Trim to a fixed length option allows reads to be trimmed to a fixed length. Bases can be trimmed from the 5' end or the 3' end.
Trimming reads to a fixed length is carried out as the final trimming action, after other trimming actions have been applied.