1: INPUT

• prepare a file that lists the protein unique identifiers (UIDs), one UID per line, up to 100,000 UIDs maximum (sample file). The UIDs should be integers only (i.e., use GI numbers, not accession numbers), and the current range of acceptable is 0 to 4294967295. The FLink help document provides additional details about valid UIDs.



• open the FLink search page.



• open the "Please choose a database to start" menu and select "Protein."



• select "Upload ID List," use the "Browse" function to find your file, then press "Submit."

2: REVIEW + SELECT

• FLink will display a "Protein" folder tab that provides a summary view of your input items, including descriptive information that FLink obtained from the Entrez Protein database for each of the input items. The folder tab lists the proteins in order of increasing UID, regardless of the order in which they were input into the system, and ignores duplicate UIDs.



• Click on the "LinkTo" function in the folder tab to open a dialog box that lists the possible destination databases and link types you can select. Click on an option to view its description in the dialog box. When you find an option of interest to you, for example, protein_biosystems, select it and press "Submit."

3: OUTPUT

• In the resulting output page, a BioSystems folder tab will display a ranked list of the biosystems that contain proteins from your input list. The "Frequency" column indicates the number of items from your input list that are associated with each retrieved record. Click on the value in that column to see which subset of items from your input list are linked to the retrieved record.



• The Download CSV function can be used to save a comma separated value file of the output.



• Tip: The URL at the top of the output page will show the Job ID for that particular LinkTo operation. You can save the URL and use it anytime during the next 24 hours to view your results again.