Tissue samples at Fruit Growers Lab

I have some otherwise healthy girls that going down branch by branch to a weird mutation at the new growth site. I'm getting my soil tested, and wanted to have some tissue test performed as well. Has anyone had FGL perform a tissue test. Would you tell them your worried your tomato plant has a disease? What is the best way to bring and prepare your sample for them?

Thanks

I think the best option is to be truthful from the outset, but there is little issue with submitting a pic here

We need pics to evaluate