An article adapted for holding a liquid sample for quantification of biological material in the liquid sample. The article includes a bag having an upper surface sheet and a lower surface sheet enclosing a volume therebetween. The bag has an upper opening through which the liquid sample can be poured into the volume in the bag. The bag also has a plurality of partitions configured to separate one or more portions of adequate sample in the bag. Also provided is a passage through which a liquid sample can be distributed throughout the volume in the bag. The bag is made of material which can be caused to form discreet non-permeable compartments for holding separate aliquots of the liquid sample.