Filtration sampling and testing devices

A sampling device for concentrating a liquid specimen sample, the sampling device comprising a filtration assembly, which comprises:

• a tubular container, which is shaped so as to define an inner wall and a proximal container opening for receiving the liquid specimen sample;
• a plunger, which (i) comprises a plunger head and a plunger rod, which has a distal end portion to which the plunger head is coupled, and (ii) is insertable into the tubular container via the proximal container opening, such that a lateral surface of the plunger head forms a fluid-tight movable seal with the inner wall of the tubular container;
• a waste liquid receptacle;
• a filter;
• a filter support, which is shaped so as to define (a) a support surface on which the filter is removably disposed, and (b) a plurality of filtrate-passage openings through the filter support into the waste liquid receptacle;
• and
• a source of gas, which is configured to provide gas by releasing or generating the gas,
• wherein the filtration assembly is configured such that providing the gas by the source of gas, when the liquid specimen sample is contained in the tubular container and the filter is disposed on the support surface, pushes at least a portion of the liquid specimen sample through the filter and the filtrate-passage openings and into the waste liquid receptacle.