### Overview of constraints

Using the Constraints section of the Settings tab, you can select the physicochemical properties that are considered in your analysis. Using the Setting column, you can specify the desired range of values for a constraint. Primers whose properties lie in the specified range are considered to pass the constraint, while primers outside the range are considered to fail the constraint. When filtering a primer set, primers failing any of the active constraints are removed from the set.

The Limit column specifies the boundary for relaxing constraints when designing primers. If no solution achieving the desired target coverage can be found, the difference between the Setting and Limit column defines the relaxation step size.

For more information on individual constraints, please select one of the constraints that are listed in the navigation panel at the top of the page.