From what I understand about Verticillium is that you can liken it to herpes... Once you get it, you have it for good. If it is in your soil, count on it still being there.

Certain Soil Test Labs can tests soil for verticillium propagules -- for a fee, but I don't know how much.

That said, you need to know where the suspected infected tree was. If not,too pricey to test everything. Instead, plant what's not susceptible. Suggested are any conifer, birch, dogwood, or sycamore.

"From what I understand about Verticillium is that you can liken it to herpes... Once you get it, you have it for good"

I also suffer with this monster, but am working on a preventative. Have a look at the link, this looks most hopeful.
http://www.biocontrol.entomology.cornell.edu/pathogens/trichoderma.html#Top

Here is a link that might be useful: Trichoderma

I knew once there it was there for good, I just want to make sure it is there and not mis-diagnosed. Ahh the soil lab was what I thought I too, thanks Jean001a. I'll start calling various labs.

So beeman gardener have you had any success with Trichoderma? I just wrote to the author and the extension office at Cornell - it will be interesting to see if they answer.

"So beeman gardener have you had any success with Trichoderma?"
Not yet, but it's very early days. I only found out about it a few weeks ago, hardly time to put it into practice.
Always next year, it's the gardeners call sign!!!