How do I see and use MW markers if they are not displayed in the default list?
SnapGene has hundreds of commercial and common molecular weight markers (MW markers) that you can use with your agarose gel simulations. Not all markers are listed by default. Follow the instructions in this lesson to add your favorite markers to the default list.
Customize the Default List of MW Markers
![](https://media.screensteps.com/image_assets/assets/004/958/273/original/2d50e4f1-ff31-4340-a35a-d4613bcd6b5a.png)
If a favorite MW marker is not listed in the MW Marker dropdown menu, click Edit MW Markers List....
![](https://media.screensteps.com/image_assets/assets/004/958/276/original/f22dd5b7-302c-4e4b-bec5-053d3738ce70.png)
Alternatively, open SnapGene Preferences by clicking SnapGene → Preferences (macOS), or by clicking Edit → Preferences (Windows or Linux). Select "Agarose Gels" and click Edit MW Markers List....
![](https://media.screensteps.com/image_assets/assets/004/958/278/original/90cf1099-d010-4dfb-bbf1-6cdbd3d6e28a.png)
Locate, the ladder or ladders you would like to use.
Click the disclosure triangles to expand each section and see all ladders for that section.
Click the check box next to a desired ladder to add it to the default list.
To remove a ladder from the default list, locate the ladder and click to uncheck.
Click OK to save the changes.
Use the Ladders
![](https://media.screensteps.com/image_assets/assets/004/958/280/original/0bd35908-d503-41ea-9b17-d3410633126c.png)
The selected ladders will now be displayed in the default list.