Sample Preperation


Microfluidic devices are ideal systems to automate various aspects of sample preparation.  We have developed several devices that are being used to derivatize, stimulate, and collect from biological samples.


Papers:
Filla, R. T.; Schrell, A. M.; Coulton, J. B.; Edwards, J. L.; Roper, M. G. “Frequency-modulated continuous flow analysis electrospray ionization mass spectrometry (FM-CFA-ESI-MS) for sample multiplexing” Anal. Chem. 2018, 90, 2414-2419.  PDF


Mukhitov, N.; Spear, J. M.; Stagg, S. M.; Roper, M. G. “Interfacing microfluidics with negative stain transmission electron microscopy” Anal. Chem. 2016, 88, 629-634.  PDF


Baker, C. A.; Roper, M. G. “Online coupling of digital microfluidic devices with mass spectrometry detection using an eductor with electrospray ionization” Analytical Chemistry 2012, 84, 2955-2960.  PDF


Yu, Y.; Li, B.; Baker, C. A.; Zhang, X.; Roper, M. G. “Quantitative polymerase chain reaction using infrared heating on a microfluidic chip” Analytical Chemistry 2012, 84, 2825-2829.  PDF

​Research​​

Fabrication of Glass Microfluidic Devices

Islets of Langerhans Dynamics

Funding

Measurement of Cellular Secretion

At Florida state university

 

The fabrication of these devices can be tricky, especially when attempting to make extremely shallow channels.  Follow this link to a protocol that we have found to have good success at making glass microfluidic chips.  This protocol has been published and should be cited if used:

Baker, C. A.; Roper, M. G. “Continuous-flow, microchip electrophoresis fraction collector” J. Chromatogr. A 2010, 1217, 4743-4748.

We are developing microfluidic devices that can deliver reagents to islets of Langerhans in complex temporal patterns to investigate how islets respond to these dynamic stimulations.

Example papers:

McKenna, J. P.; Dhumpa, R.; Mukhitov, N.; Roper, M. G.; Bertram, R. “Glucose oscillations can activate an endogenous oscillator in pancreatic islets” PLoS Comput. Biol. 2016, 12, e1005143.  PDF


Dhumpa, R.; Truong, T. M.; Wang, X.; Roper, M. G. "Measurement of the entrainment window of islets of Langerhans by microfluidic delivery of a chirped glucose waveform" Integrative Biology2015, 7, 1061-1067.  PDF


Yi, L.; Wang, X.; Dhumpa, R.; Schrell, A. M.; Mukhitov, N.; Roper, M. G. "Integrated perfusion and separation systems for entrainment of insulin secretion from islets of Langerhans" Lab on a Chip 2015, 15, 823-832. PDF


Dhumpa, R.; Truong, T. M.; Wang, X.; Bertram, R.; Roper, M. G. “Negative feedback synchronizes islets of Langerhans” Biophysical Journal2014, 106, 2275-2282.  PDF

Zhang, X.; Daou, A.; Truong, T. M.; Bertram, R.; Roper, M. G. “Synchronization of mouse islets of Langerhans by glucose waveforms”  American Journal of Physiology - Endocrinology and Metabolism 2011, 301, E742-E747.  PDF


We utilize fast capillary electrophoresis separations for high speed monitoring of cellular secretion.  We also use multi-color laser-induced fluorescence detection for achieving spectral resolution in cases where spatial resolution is limited. 

Example papers:


​Bandak, B.; Yi, L.; Roper, M. G. “Microfluidic-enabled quantitative measurements of insulin release dynamics from single islets of Langerhans in response to 5-palmitic acid hydroxy stearic acid” Lab Chip2018, doi: 10.1039/c8lc00624e.  PDF


Wang, X.; Yi, L.; Roper, M. G. “Microfluidic device for the measurement of amino acid secretion dynamics from murine and human islets of Langerhans” Anal. Chem. 2016, Analytical Chemistry 2016, 88, 3369-3375. PDF


Yi, L.; Wang, X.; Bethge, L.; Klussmann, S.; Roper, M. G. “Noncompetitive affinity assays of glucagon and amylin using mirror-image aptamers as affinity probes” Analyst 2016, 141, 1939-1946. PDF


Wang, X.; Yi, L.; Guillo, C.; Roper, M. G. "Micellar electrokinetic chromatography method for measuring amino acid secretions from islets of Langerhans" Electrophoresis 2015, 36, 1172-1178.  PDF


Yi, L.; Wang, X.; Dhumpa, R.; Schrell, A. M.; Mukhitov, N.; Roper, M. G. "Integrated perfusion and separation systems for entrainment of insulin secretion from islets of Langerhans" Lab on a Chip 2015, 15, 823-832. PDF