In a method for performing ultrasound tests which uses a suitable device for performing such tests, a well plate implements an insulation between the different wells of the plate of such set, without significant reflections of ultrasounds which could alter the test itself since the well plate is covered by means for closing said wells which insulates the content thereof by wholly covering the well plate and having a sound transmission speed which differs from that of the transmission liquid in the bath no more than +/−15%.