You should try to find a cleaning service that has specialized experience with mold. Mold can be very difficult to test for if you don't know what you're looking for. This can't be done by just any company out there. The company needs to have specialized equipment and access to testing facilities. If you only hire a company that meets these standards, then you won't be wasting your time on someone that can't help you.

Make sure that the cleaning service is licensed to deal with mold. This is a very important consideration for you to keep in mind. Mold can be a very dangerous thing to deal with. This is why mold testing and removal is so heavily regulated at the state and local level. You should never hire a cleaning service to do mold testing for you if it is not a licensed business.

You should call ahead and ask about the fee you will be charged for the mold testing. Any cleaning service that does mold testing commercially will be able to quickly quote you a standard price for testing services.