See also
OTU / denoising
pipeline
The table below summarizes the read preparation steps that I recommend for an OTU / denoising pipeline. Follow the links for details.
Step | Description | |
Understand your reads | Investigate your reads, don't blindly follow a recipe | |
Demultiplex | Assign reads to samples using index reads or barcodes | |
Merge pairs | Merge paired reads to get consensus sequences and Q scores | |
Strip primers | Primer-binding sequence should be removed before quality filtering | |
Orient | If you have reads on both strands, orient before trimming and finding uniques | |
Strip machine sequences | Remove machine-specific sequences e.g. TCAG for 454 | |
Length trimming | Remove low-quality tails, make sure 3' ends align | |
Quality filtering | Making OTUs (but not the OTU table) needs high-quality reads | |
Pool samples | Reads for all samples should be combined | |
Discard singletons | Remove low-abundance reads, which often have errors |