Entering edit mode
4.5 years ago
RhiRhiO
•
0
Hello,
our lab sequenced 90 libraries this week which were tagged with Illumina's i5 and i7 indexes. By mistake the sequencer was set to use one index instead of two. Is there a way to distinguish the libraries? Thanks for your help.
Was the sequencing done by you or a facility? If a facility they should (must) repeat the run as part of their warranty duties. I doubt that with 90 samples and a single-index run you have a unique index for every sample. Can you give details? Are the sequenced indices unique?
The run was done at the platform but the machine was set up by us, so it's our own fault. The combination of indices is unique for each sample (single cell) but as we chose single index setting I can't demultiplex. I am just wondering if there's another way to separate the libraries.
As long as all sample indexes are unique you can demultiplex the data. You can change the samplesheet to contain only the index that was sequenced. You can then demultiplex the run either via BaseSpace or using
bcl2fastqon the command line (or on the machine itself).Agree on this. As long as you have 90 different and unique i7s (I guess this was used and not the i5) then you can demultiplex it as any single-index run.
Sounds like only the combinations are unique, not index1 alone.
That is exactly what I am asking OP to clarify on. 90 unique i7s is a bit unlikely in a standard setup (I guess, at least I would not do it that way), that is why dual-indexing exists.
Yes unfortunately only the combination of indexes are unique.
I fear that means resequencing :(