Separation and Extraction of DNA from DNA-Protein Mixtures Using a Microfluidic Process

A microfluidic process utilizing a combination of flows and electric
fields is used to separate long strands of DNA from proteins. The
separation relies on DNA migrating to the bounding walls of a
microfluidic channel and then upstream against the strong pressure
driven flow due to an opposing electrophoretic velocity [1,2]. As a
result, DNA is trapped within the microfluidic channel, but proteins,
which do not migrate to the bounding walls, are swept out of the channel
by the convective flow. In this work, we separate mixtures of DNA
(lambda phage DNA) and proteins such as bovine serum albumin (BSA).
Measurements of in-situ fluorescence confirm the separation, as done
previously [3]. Additionally, the DNA is recovered from the
microfluidic chip and analyzed. Extraction efficiency and yields are
reported as a function of flow and field strengths using UV-vis
spectrophotometry and quantitative fluorometry. The length distribution
of the recovered DNA is also reported.

[1] Mert Arca, Anthony J.C. Ladd, and Jason E. Butler,
“Electro-hydrodynamic concentration of genomic length DNA,” Soft Matter
12, 6975-6984, 2016.

[2] Ryan J. Montes, Anthony J.C. Ladd, and Jason E. Butler, “Transverse
migration and microfluidic concentration of DNA using Newtonian
buffers,” Biomicrofluidics 13, 044104, 2019.

[3] Benjamin E. Valley, Anne D. Crowell, Jason E. Butler, and Anthony
J.C. Ladd, “Electrohydrodynamic extraction of DNA from mixtures of DNA
and bovine serum albumin,” Analyst 145, 5532-5538, 2020.