The metadata file allows you to group forward and reverse FASTQ files for the same sample, assign a short sample ID, and give the samples group labels (Ie. treatment, control). If you have more than one metadata, just choose the most important. They are just used for labelling QA/QC plots, and you can input more group labels prior to performing downstream statistical analysis.
The file should be a tab-delimited .txt file formatted like this:
You can easily create this by opening a new table in Excel, and then “Save as …” a “Tab delimited Text (.txt)” file.
If you have a single-read dataset, just omit the “reverse_file” column.