Vibrating machine with cam driven sample holders

A vibrating machine, for extracting, mixing and separating organic and inorganic materials, both in liquid and powder form, in particular for preparing samples for analyzing DNA, wherein said vibrating machine comprises a framework slidably supporting two opposite supporting shoulders each holding therein a respective test tube vessel containing a plurality of test tubes, said supporting shoulders being coupled to a pair of parallel guides rigid with said framework of said vibrating machine, each said supporting shoulder being rigidly coupled to cam follower means affected by a cam in turn driven by a variable speed electronically controlled electric motor, to cause said test tube supporting shoulders to perform a rectilinear symmetrically opposite reciprocating movement, and wherein said cam follower means are rigidly coupled by rigid arm means to said shoulders.