I personally would skip the biomeridian testing especially since its so expensive. Is it like $1000?? The MELISA is I believe $500 or something close to that for 5 metals, if I'm not mistaken.
For the metals, it would have to be inorganic mercury for one, then probably the other 5 in Amalgams such as palladium, tin, nickel and also methylmercury and maybe lead.
The biocompatibility test could be helpful but my dentist is very on top of the "newest and best" materials in terms of everything so I skipped it and am going with his recommendations.