Materials and Reagents

1. Glycerol stock of Pseudomonas aeruginosa (P. aeruginosa) (acquired from a single colony, stored at -80 °C)
   
2. Bacto-tryptone (BD Biosciences, catalog number: 211705 )
   
3. Sodium chloride (Sigma-Aldrich, catalog number: S7653 )
   
4. Colistin sodium sulfate (Sigma-Aldrich, catalog number: C4461 )
   
5. Polydimethylsiloxane (PDMS) (Sylgard 184 Silicone Elastomer Kit) (Dow Corning Corporation)
   
6. Petri dishes (150 mm x 15 mm) (VWR International, catalog number: 25384-326 )
   
7. 100% Ethanol
   
8. Sterile dH₂O
   
9. LIVE/DEAD BacLight Bacterial Viability Kit with Syto9/Propidium Iodide (Life Technologies, catalog number: L-7012 )
   
10. 1% TB liquid medium (see Recipes)
    

Equipment

1. Sterile 14 ml polystyrene culture tubes (VWR International, catalog number: 60818-725 )
   
2. Sterile 1 μl plastic loops (Santa Cruz, catalog number: SC-200266 )
   
3. Spectrophotometer for absorbance readings
   
4. 37 °C shaking incubator
   
5. Microfluidic channel molds (Figure 1)
   
   
   Figure 1. Microfluidic channels. Each channel is 100 μm deep and 500 μm wide. The 10 channels were fabricated by depositing SU-8 2150 on silicon wafers using standard soft lithography techniques (Xia and Whitesides, 1998). This device allows for 10 parallel experiments.
   
   
6. SU-8 2150 (MicroChem Corp.)
   
7. Glass Slides (75 x 50 mm) (Ted Pella, catalog number: 26005 ) or cover glass (75 x 50 mm) (Ted Pella, catalog number: 260462 )
   
8. Lens paper
   
9. Desiccator with vacuum line
   
10. Exacto-knife or scalpel
    
11. 5 ml syringes (BD, catalog number: 309647 )
    
12. Polyethylene tubing (ID 0.58 mm, OD 0.965) (BD, Intramedic^TM, Clay Adams^®, catalog number: 427411 )
    
13. Harris Unicore hole punch (1.20 mm) (Ted Pella, catalog number: 15074 )
    
14. Hand-held corona generator (Laboratory Corona Treater, Electro-Technic Products, Model: BD-20AC )
    
15. Syringe pump with 10-syringe holder adaptor (Harvard Apparatus)
    
16. Fluorescence microscope with automated focus/stage system (e.g., Nikon TE2000-E equipped with an Andor iXon-885 and a 40x long working distance objective)
    

Software

1. ImageJ

Procedure