We utilize fast analytical systems 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:

​Adams, A. G.; Bulusu, R. K. M.; Mukhitov, N.; Mendoza-Cortes, J. L.; Roper, M. G. "Online measurement of glucose consumption from HepG2 cells using an integrated bioreactor and enzymatic assay" Analytical Chemistry2019, 91, 5184-5190.PDF

Evans, K.; Wang, X.; Roper, M. G. "Chiral micellar electrokinetic chromatographic separation for determination of L- and D-primary amines released from murine islets of Langerhans" Analytical Methods, 2019, 11, 1276-1283.PDF

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 on a Chip2018, 18, 2873-2882.  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” Analytical Chemistry2016, 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” Analyst2016, 141, 1939-1946. PDF

Measurement of Cellular Secretion

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” Journal of Chromatography A 2010, 1217, 4743-4748.

Fabrication of Glass Microfluidic Devices

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.

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” Analytical Chemistry201890, 2414-2419.  PDF

Mukhitov, N.; Spear, J. M.; Stagg, S. M.; Roper, M. G. “Interfacing microfluidics with negative stain transmission electron microscopy” Analytical Chemistry2016, 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 201284, 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 201284, 2825-2829.  PDF

Islets of Langerhans Dynamics


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:

Mukhitov, N.; Adablah, J. E.; Roper, M. G. "Gene expression patterns in synchronized islet populations" Islets2019,11, 21-32.PDF

Adablah, J. E.; Vinson, R.; Roper, M. G.; Bertram, R. "Synchronization of pancreatic islets by periodic or non-periodic muscarinic agonist pulse trains" PLoS One2019, 14, e0211832.PDF

McKenna, J. P.; Dhumpa, R.; Mukhitov, N.; Roper, M. G.; Bertram, R. “Glucose oscillations can activate an endogenous oscillator in pancreatic islets” PLoS Computational Biology2016, 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 Chip2015, 15, 823-832. PDF

At Florida state university