Synchronized Islet Population :

Non-synchronizedIslet Population :

Measurement of Cellular Secretion

Islets of Langerhans Dynamics

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.

Fabrication of Glass Microfluidic Devices

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:

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:


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


Lomasney, A. R.; Li, Y.; Roper, M. G. “Simultaneous monitoring of insulin and islet amyloid polypeptide secretion from islets of Langerhans on a microfluidic device” Analytical Chemistry 2013, 85, 7919-7925.  PDF

​Research​​

Pancreatic islets were stimulated on a microfluidic device and live cell imaging was performed using an intercellular calcium dye (Fura-2 AM)

Sample Preperation

At Florida state university

 

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:

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


Duong, C. T.; Roper, M. G. “A microfluidic device for the automated derivatization of free fatty acids to fatty acid methyl esters” Analyst 2012, 137, 840-846. PDF


Baker, C. A.; Bulloch, R.; Roper, M. G. “Comparison of separation performance of laser-ablated and wet-etched microfluidic devices” Analytical and Bioanalytical Chemistry 2011, 399, 1473-1479.  PDF


Baker, C. A.; Roper, M. G. “Continuous-flow, microchip electrophoresis fraction collector” Journal of Chromatography A 2010, 1217, 4743-4748. PDF