One of the most prevalent types of Circulating Tumor Cell (“CTC”) enrichment technique is the filtration method. Those methods are based on physical properties that allow isolation of CTC’s by size. CTC’s are generally larger in size than hematopoietic cells, so those are retained whereas most hematopoietic cells pass through the filter.

The size‐based isolation of CTC’s was initially explored by using polycarbonate filters. Here is presented the imaging of one of these filters.