Direct detection of nanoparticles and hMW DNA in whole blood “seamless sample to answer diagnostics”

Abstract

In medical research and diagnostics, it is a significant challenge to directly isolate and identify rare cells, biomarkers such as high molecular weight DNA nanoparticulates and immunocomplexes, and drug delivery nanoparticles directly in blood. We have now demonstrated the isolation and detection of nanoparticles and high molecular weight DNA (hmw DNA) from whole blood using a microarray dielectrophoretic (DEP) device. Both fluorescent nanoparticles and fluorescent‐stained hmw DNA in undiluted whole blood samples were separated and held in DEP high field regions and then detected after the blood cells were removed by a fluidic wash. In buffy coat blood, with reduced cell numbers, 40nm nanoparticles concentrated into the DEP high field regions while the blood cells concentrated into the DEP low field regions. Overall, this work sets the stage for a new generation of "seamless" sample to answer diagnostic systems; i.e., a process where a complex sample is run through a device, and the specific analytes are rapidly concentrated onto microscopic locations and subsequently detected. Such devices will allow highly complex clinical and other biological samples such as blood, plasma and serum to be rapidly and directly analyzed for rare cells, DNA biomarkers and drug delivery nanoparticles. Work supported by the NIH‐NCI Center Grant (U54‐CA119335).