Plugin error from demux: Mismatched sequence descriptions

Hello All,

I am currently embarking on the transition from QIIME 1 to QIIME 2 and using a tutorial based off of the QIIME 2 docs to conduct the analysis. I was attempting to demultiplex, however I received the following error after running the command to demultiplex:

Plugin error from demux:

** Mismatched sequence descriptions: N:0:1, N:0:CAGTGCATATGC, and N:0:CAGTGCATATGC**

Debug info has been saved to /tmp/qiime2-q2cli-err-0rujhiem.log

the referenced log file is copied below:
Traceback (most recent call last):
File “/home/qiime2/miniconda/envs/qiime2-2018.2/lib/python3.5/site-packages/q2cli/”, line 246, in call
results = action(**arguments)
File “”, line 2, in emp_paired
File “/home/qiime2/miniconda/envs/qiime2-2018.2/lib/python3.5/site-packages/qiime2/sdk/”, line 228, in bound_callable
output_types, provenance)
File “/home/qiime2/miniconda/envs/qiime2-2018.2/lib/python3.5/site-packages/qiime2/sdk/”, line 363, in callable_executor
output_views = self._callable(**view_args)
File “/home/qiime2/miniconda/envs/qiime2-2018.2/lib/python3.5/site-packages/q2_demux/”, line 331, in emp_paired
for barcode_record, forward_record, reverse_record in seqs:
File “/home/qiime2/miniconda/envs/qiime2-2018.2/lib/python3.5/site-packages/q2_demux/”, line 211, in iter
ValueError: Mismatched sequence descriptions: N:0:1, N:0:CAGTGCATATGC, and N:0:CAGTGCATATGC

I appreciate any information/help/insight anyone has to offer regarding this error. Thank you in advanced for any guidance you have regarding this error.

Hey there @ykhan!

This means that the record id in your barcode reads (N:0:1) don’t match up or align to the record ids in your forward/reverse reads (N:0:CAGTGCATATGC), for at least one record.

How were these data processed or prepared? Did they follow the EMP protocol?

Hey @thermokarst,

As far as I know they were prepared using EMP protocol. I downloaded the run data off of BaseSpace but previously I would download directly from the sequencer. I plan on downloading directly and running the workflow again, to see if there is any change. Do you think this will have an effect?

I don’t know!

If the EMP protocol was used on the sequencing and data prep side of things, these IDs should all match. I would contact your sequencing center to see if they can provide a bit more detail. Keep us posted! :qiime2: :t_rex:

Hi Yasmin, I´m also having the same problem. Did you sequence your samples in a service provider?

Hello @thermokarst & @FranciscoC,

Sequencing was done at our lab so I was able to download the files directly from the MiSeq. After running demux using these files instead of what was downloaded from BaseSpace, I did not receive the above error or any other errors for that matter and the script ran to completion.

The only thing I can think of for the error occurring would be incorrect files downloaded from BaseSpace but I solely had the option to download the Run data and couldn’t really download much else. These files saved as Undetermined_R1 and R2 respectively, so I feel as though this is why this error occurred. @FranciscoC how did you obtain your data? Did you also download the data or was it sent from a sequencing facility ?

1 Like

Hello ykhan. Sorry for the late reply. I obtained my data trough a service provider through BaseSpace.

This topic was automatically closed 31 days after the last reply. New replies are no longer allowed.