(a) Back pulses (indicated by dotted lines) reduce filter contamination without affecting the count of cancer cells on the filter.
(b-d) Representative composite images from (b) before wash, (c) after 8 ml of wash and one pulse, and
(d) after 18 ml of wash and two pulses.
(e) Contamination can be significantly reduced using back pulses, to below the point of “fast flow” conditions, but without sacrificing efficiency to do so.
The optimized wash from Figure 4 is also compared.