A homogeneous assay for protein analysis in droplets by fluorescence polarization.
We present a novel homogeneous ("mix-incubate-read") droplet microfluidic assay for specific protein detection in picoliter volumes by fluorescence polarization (FP), for the first time demonstrating the use of FP in a droplet microfluidic assay. Using an FP-based assay we detect streptavidin concentrations as low as 500 nM and demonstrate that an FP assay allows us to distinguish droplets containing 5 μM rabbit IgG from droplets without IgG with an accuracy of 95%, levels relevant for hybridoma screening. This adds to the repertoire of droplet assay techniques a direct protein detection method which can be performed entirely inside droplets without the need for labeling of the analyte molecules.
Division of Nanobiotechnology, Royal Institute of Technology (KTH), Albanova University Center, Stockholm, Sweden. hakan.jonsson@biotech.kth.se
Haakan N
HN
Joensson
Chi
C
Zhang
Mathias
M
Uhlén
Helene
H
Andersson-Svahn
D000818:Animals; D004867:Equipment Design; D019793:Fluorescein / Q000737:chemistry; D005454:Fluorescence Polarization / Q000379:methods*; D007118:Immunoassay; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D011506:Proteins / Q000032:analysis*; D011817:Rabbits
D011506:Proteins; D019793:Fluorescein