Preparing samples for shipment is a critical stage of every study, and the scope of the service may also include nucleic acid extraction from the supplied material for water samples. To prepare samples correctly without risking material loss or sample depletion, follow the instructions below:
Water sample collection instructions
Water filters should have a diameter of 4 cm. We recommend using at least 3 filters per sample, with visible coloured deposits on the filters.
Before centrifugation, assess whether the water contains a large number of organisms. If the biological content of the water is low, centrifuge at least 50 ml of water. If the biological content is high, centrifuge an appropriate volume from 2 to 10 ml.
Additional information
A. For filtering large volumes of low-biomass water samples, use polyethersulfone filters with a pore size of 0.22 μm. Each sample should include at least 1 litre of water.
B. For turbid water samples that filter slowly or are prone to clogging 0.22 μm filters, mixed cellulose ester filters with a pore size of 0.45 μm are recommended (cellulose acetate, cellulose nitrate). Avoid these filters if the water contains insecticides and herbicides. Each sample should contain 0.5-1 litre of water. If clogging occurs, store multiple filters from the same sample in a single tube.
C. If the water sample contains a large number of insoluble particles, use filters with a pore size of 2-5 μm to remove insoluble contaminants, and then use filters with a pore size of 0.22 μm or 0.45 μm to concentrate microorganisms. Each sample should contain 0.5-1 litre of water. If the filters become clogged, store multiple filters from the same sample in a single tube.
D. If the study focuses on viruses, first remove bacteria and other large cells from the water using filters with a pore size of 0.22 μm, and then use positively charged filters, such as Virozorb 1 MDS cartridges or NanoCeram Virus Sampler, to concentrate the viruses. Each sample should contain 20 litres of water.