PhD Defense: "Nano to Micro Scale Coulter Counters"

Sukru Yemenicioglu

September 1st (Tuesday), 10:00am
Elings Hall (CNSI), Room 1605

As biotechnology continues on advancing, one of the trends that has become prominent in recent years is personalized medicine. It is an endeavor that can be briefly described as an effort to provide preventative, diagnostic and treatment measures against health problems implemented on an individual basis. Resistive pulse technique is a measurement scheme that has found a wide range of applications in this field. In my doctoral defense, I will present my research on devices that are based on resistive pulse technique from nano to micro scale. I will briefly report my research on the use of synthetic nanopores for DNA sequencing research and biomolecule sorting. Then, I will talk about a micro scale application of this technique for cancer diagnosis. Particularly, Circulating Tumor Cells(CTCs) have recently emerged as indicators of cancer metastasis. Thus, efficient detection of CTCs can provide non-invasive biopsy, enable personalized medicine and help understand cancer biology. Currently used immunoassay based CTC detection techniques are inefficient and insufficient to classify extremely heterogeneous CTCs such as Circulating Melanoma Cells(CMCs). Cancer cells have markedly different physical attributes, such as size and stiffness, and can be used to distinguish tumor cells from normal cells. In this talk, I am going to report a micro-fluidic chip potentially meeting the urgent need to detect individual CTCs in a label-free, fast and inexpensive fashion while maintaining cell viability. The chip uses resistive pulse technique coupled with controlled pressure gradients to measure size and stiffness of cells without subjecting cells to large shearing forces. I am going to present the design, fabrication and modeling of microfluidic channels enabling the classification of CTCs based on their size and stiffness. Using coupled Nernst-Planck and Navier-Stokes models in COMSOL subtle features in the current profile are corroborated with the size, angle of entry and stiffness. The insight provided by careful modeling of these devices enables accurate classification and clustering, which would not otherwise be possible. Validity of the modeling was proven by sizing commercially available 10um polystyrene particles and matched results obtained by optical microscopy analysis. The device was used to classify melanoma (MNT1)and breast cancer (MCF-7) cells both with and without blood cells. Results show the interference due to the presence of blood cells is minimal demonstrating the reliability of the device in detecting CTCs from a blood sample.

About Sukru Yemenicioglu:

photo of sukru yemenicioglu. Sukru Yemenicioglu completed his bachelors and masters degrees in electrical engineering in University of Illinois Urbana Champaign. During his undergraduate study, he joined Prof Gregory Timp's group, where he began working on solid-state nanopore sensors. He continued his research in Prof. Rashid Bashir’s research group, investigating alternative membrane structures for synthetic nanopore research. During his PhD in Biomimetic Circuits and Systems Group in UCSB, his research focused on biosensors based on Coulter Counters.

Hosted by: Professor Luke Theogarajan