If "isolate" means to separate from others:
* Connect: To bring together, unite, or join.
* Integrate: To combine or blend into a whole.
* Unite: To join or bring together into one.
* Include: To make part of a whole or group.
If "isolate" means to make something stand alone:
* Combine: To join together or merge.
* Connect: To link or join.
* Integrate: To incorporate or blend into a whole.
* Relate: To show or establish a connection between things.
If "isolate" means to find the sole cause of something:
* Combine: To merge or join together multiple causes.
* Analyze: To examine the various contributing factors.
* Investigate: To examine thoroughly to find the underlying causes.
To find the most accurate opposite, consider the context in which "isolate" is used.