Yanlin Li
Brandeis University / Physics
Hosted by Fraden's Lab
“Counter Diffuse Microfluidic Chips for Protein Crystallization”
Yanlin Li, S.Ali Aghvami, Seth Fraden
Abstract
Proteins are an essential component of all organisms. Thus the understanding of protein structures is critical in many industries, including pharmaceutics and nutrition. Protein crystals facilitate analysis of protein structure. In order to crystalize proteins, salts are added to protein solutions to enhance the bonding between molecules, and the challenge is to determine the right concentration of salts versus proteins. My objective was to design a microfluidic device (chip) that can monitor different crystallization recipes at the same time.
In this design, multiple salt solutions are loaded into the chip separately. Then protein solutions are added to each salt solution in a manner such that only protein and salts will contact but different salt solutions will not mix. The flow of fluids on the chip is controlled by pressure difference across capillary valves and finding the correct dimensions of each valve was one of my principal tasks.
The final design that was found successful contains six capillary valves separated into two layers. The chip was made out of PDMS and liquids were loaded by syringe pump, which operates by controlling the flow rate. My next plan is to add a mechanical screw onto the chip to supplement the capillary valves. A subsequent objective is to replace the syringe pump with a device that induces flow by controlling pressure. Additionally, I will design chips that can monitor recipes with precipitants in different volumes.
Support: SMURF (Summer MRSEC Undergrad Research Fellowship)