2

Materials

Long-lasting thermoplastic materials are preferred for the fabrica-

tion of the microfluidic devices presented here. In our previous

studies, polystyrene (PS), poly(methyl methacrylate) (PMMA)

and cyclo olefin polymer (COP) were compared to each other and

COP was selected as a base material due to its low auto-fluorescence

and high rigidity [4]. Detailed information about thermoplastics

can be found in the article Genc¸tu¨rk et al. [2]. COP under the

brand name Zeonor with product code 10-0672-0349-1.0-05 was

purchased from Microfluidic ChipShop Company (Jena, Ger-

many). The chemicals and reagents for medium preparation and

cleaning were bought from Sigma-Aldrich (Taufkirchen, Ger-

many). Polyethylene tubing with BB31695-PE/p product code

and 5 min epoxy are were purchased from Scientific Commodities

Inc. SCI (Lake Havasu City, AZ 86406, USA) and BISON (Rot-

terdam, The Netherlands), respectively.

3

Methods

All solutions that require water are made using distilled water.

Preparation and storage of all reagents and chemicals are done at

room temperature under clean laminar flow hood. All of the ther-

moplastic chip fabrication steps are accomplished in clean room.

Waste materials were collected in biological waste bags and

removed from the laboratory following the necessary procedures.

Fabrication steps of the device is summarized in the following

figure (Fig. 1).

3.1

Thermoplastic

Chip Design and

Preparing Its Mold

The main purpose of the design in microfluidic devices for cultiva-

tion is to trap and keep cells in predefined areas, where real time

monitoring of cells of interest can easily be accomplished. Thus,

c-shaped regions that provide cell trapping in the channels of the

chip are designed (Fig. 2a), and the high-quality images (bright-

field and fluorescence) of the trapped cells are taken throughout the

experiment.

3.1.1

Photolithography

1. Draw the microfluidic devices using AutoCAD software

(Fig. 2a).

2. Use COMSOL software and determine flow dynamics within

the microfluidic device. Determine the flow rate required for

cell trapping in the c-shaped regions.

3. Transfer finalized design to acetate paper to be used in the

photolithography process with the help of an external high

resolution printer with 3000 or higher dot-per-inch (dpi).

Fabrication Protocol for Thermoplastic Microfluidic Devices: Nanoliter. . .

29