TY - JOUR
T1 - Highly efficient assay of circulating tumor cells by selective sedimentation with a density gradient medium and microfiltration from whole blood
AU - Park, Jong Myeon
AU - Lee, June Young
AU - Lee, Jeong Gun
AU - Jeong, Hyoyoung
AU - Oh, Jin Mi
AU - Kim, Yeon Jeong
AU - Park, Donghyun
AU - Kim, Minseok S.
AU - Lee, Hun Joo
AU - Oh, Jin Ho
AU - Lee, Soo Suk
AU - Lee, Won Yong
AU - Huh, Nam
PY - 2012/9/4
Y1 - 2012/9/4
N2 - Isolation of circulating tumor cells (CTCs) by size exclusion can yield poor purity and low recovery rates, due to large variations in size of CTCs, which may overlap with leukocytes and render size-based filtration methods unreliable. This report presents a very sensitive, selective, fast, and novel method for isolation and detection of CTCs. Our assay platform consists of three steps: (i) capturing CTCs with anti-EpCAM conjugated microbeads, (ii) removal of unwanted hematologic cells (e.g., leukocytes, erythrocytes, etc.) by selective sedimentation of CTCs within a density gradient medium, and (iii) simple microfiltration to collect these cells. To demonstrate the efficacy of this assay, MCF-7 breast cancer cells (average diameter, 24 μm) and DMS-79 small cell lung cancer cells (average diameter, 10 μm) were used to model CTCs. We investigated the relative sedimentation rates for various cells and/or particles, such as CTCs conjugated with different types of microbeads, leukocytes, and erythrocytes, in order to maximize differences in the physical properties. We observed that greater than 99% of leukocytes in whole blood were effectively removed at an optimal centrifugal force, due to differences in their sedimentation rates, yielding a much purer sample compared to other filter-based methods. We also investigated not only the effect of filtration conditions on recovery rates and sample purity but also the sensitivity of our assay platform. Our results showed a near perfect recovery rate (∼99%) for MCF-7 cells and very high recovery rate (∼89%) for DMS-79 cells, with minimal amounts of leukocytes present.
AB - Isolation of circulating tumor cells (CTCs) by size exclusion can yield poor purity and low recovery rates, due to large variations in size of CTCs, which may overlap with leukocytes and render size-based filtration methods unreliable. This report presents a very sensitive, selective, fast, and novel method for isolation and detection of CTCs. Our assay platform consists of three steps: (i) capturing CTCs with anti-EpCAM conjugated microbeads, (ii) removal of unwanted hematologic cells (e.g., leukocytes, erythrocytes, etc.) by selective sedimentation of CTCs within a density gradient medium, and (iii) simple microfiltration to collect these cells. To demonstrate the efficacy of this assay, MCF-7 breast cancer cells (average diameter, 24 μm) and DMS-79 small cell lung cancer cells (average diameter, 10 μm) were used to model CTCs. We investigated the relative sedimentation rates for various cells and/or particles, such as CTCs conjugated with different types of microbeads, leukocytes, and erythrocytes, in order to maximize differences in the physical properties. We observed that greater than 99% of leukocytes in whole blood were effectively removed at an optimal centrifugal force, due to differences in their sedimentation rates, yielding a much purer sample compared to other filter-based methods. We also investigated not only the effect of filtration conditions on recovery rates and sample purity but also the sensitivity of our assay platform. Our results showed a near perfect recovery rate (∼99%) for MCF-7 cells and very high recovery rate (∼89%) for DMS-79 cells, with minimal amounts of leukocytes present.
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U2 - 10.1021/ac3011704
DO - 10.1021/ac3011704
M3 - Article
C2 - 22881997
AN - SCOPUS:84865734178
VL - 84
SP - 7400
EP - 7407
JO - Analytical Chemistry
JF - Analytical Chemistry
SN - 0003-2700
IS - 17
ER -