How do I trim a files History?
By default, a SnapGene sequence file embeds all of the ancestral files that contributed to the current Sequence. The ancestral sequences can be viewed and restored via History view. Extensive History trees can result in very large SnapGene files. Trim a files "History" to reduce the file size.
Open a File
Open a file with History information in SnapGene.
Switch to History View
Switch to History view to see all sequences and "edits" that contributed to the Sequence file.
Trim a Specific Branch
Click on an Operation label to select it (in this example "Change Methylation"), then click Edit History → Erase Selected Operation Plus Ancestors.
All ancestors on the branch preceding (below) the selected operation are removed.
Trim All History Branches to a Set Level
In History view click Edit History → Trim History Tree....
In the Dialog that opens use the dropdown to set the level for trimming, or click and type to enter the number of levels for trimming. Click Trim to Trim the History tree.
All branches are trimmed to the set level, in this example, the History is trimmed and shows the sequence and 1 level of Ancestral sequences.
Save the file to permanently trim the ancestral information.
If you make a mistake when trimming History you can undo via menu Edit → Undo