Enclosing holder for processing a sample in a container

An enclosing holder for a sealed sample container for use in a mechanical shaker, comprising:

• a) a holder base comprising an interior cavity having a bottom surface and a top opening, said holder base comprising a sample container-engaging feature and a first closure engagement feature;
• and
• b) a holder top comprising a mated closure engagement feature adapted to removably engage with said first closure engagement feature to form a leak-proof seal, and further comprising a second sample container-engaging feature;
• wherein, when the first closure engagement feature is engaged with the mated closure engagement feature, the enclosing holder forms an air-tight enclosed space that limits or prohibits motion with respect to the enclosing holder of a sealed sample container enclosed in the enclosed space.