Extracting a subset of a database

After download, it is possible to select a subset of sequences and saving the reduced list in a new sequence list. This can reduce subsequent analysis runtime significantly.

For example, from a collection of bacterial genomes that include multiple representatives of each genus, you can extract a genus specific subset of sequences to a new list:

  1. Open the downloaded bacterial genomes database.
  2. Switch to tabular element mode (Image table).
  3. Filter towards the desired genus (figure 18.2).

    Image subset_ncbi
    Figure 18.2: The downloaded NCBI bacterial genomes database was filtered for Salmonella data. A subset of 44 out of 2,253 sequences matched this search criterion.

  4. Select all remaining rows.
  5. Click the Create New Sequence List button.
  6. Save the subset reference list.

Another way to extract a subset of a database is to make use of the Split Sequence List tool. For more information, see https://resources.qiagenbioinformatics.com/manuals/clcgenomicsworkbench/current/index.php?manual=Split_Sequence_List.html.