Dielectrophoretic isolation and detection of cancer-related circulating cell-free DNA biomarkers from blood and plasma

In this article, the authors used Biological Dynamic ACE technology to isolate cfDNA from unprocessed blood and plasma from patients with CLL. The authors used fluorescent imaging to confirm the presence of cfDNA, followed by elution for PCR and DNA sequencing.

Sonnenberg A, Marciniak JY, Skowronski EA, Manouchehri S, Rassenti L, Ghia EM, Widhopf GF, Kipps TJ, Heller MJ. Electrophoresis. 2014 May 14. doi: 10.1002/elps.201400016


Conventional methods for the isolation of cancer-related circulating cell-free (ccf) DNA
from patient blood (plasma) are time consuming and laborious. A DEP approach utilizing
a microarray device now allows rapid isolation of ccf-DNA directly from a small volume
of unprocessed blood. In this study, the DEP device is used to compare the ccf-DNA
isolated directly from whole blood and plasma from 11 chronic lymphocytic leukemia
(CLL) patients and one normal individual. Ccf-DNA from both blood and plasma samples
was separated into DEP high-field regions, after which cells (blood), proteins, and other
biomolecules were removed by a fluidic wash. The concentrated ccf-DNA was detected
on-chip by fluorescence, and then eluted for PCR and DNA sequencing. The complete
process from blood to PCR required less than 10 min; an additional 15 min was required
to obtain plasma from whole blood. Ccf-DNA from the equivalent of 5 uL of CLL blood
and 5 uL of plasma was amplified by PCR using Ig heavy-chain variable (IGHV) specific
primers to identify the unique IGHV gene expressed by the leukemic B-cell clone. The
PCR and DNA sequencing results obtained by DEP from all 11 CLL blood samples and
from 8 of the 11 CLL plasma samples were exactly comparable to the DNA sequencing
results obtained from genomic DNA isolated from CLL patient leukemic B cells (gold