Aptamer-Assisted Acoustophoresis for Microfluidic Separation of Gram-Negative Bacteria

Abstract

Source: Choi, H. J., et al. Microfluidic Acoustophoresis for Flowthrough Separation of Gram-Negative Bacteria using Aptamer Affinity Beads. J. Vis. Exp. (2022)

This video demonstrates the method of selectively separating Gram-negative bacteria from a mixed bacterial sample using aptamer-coated microbeads and acoustic forces within a microfluidic chip.

Protocol

1. Acoustophoresis setup and operation
   1. Connect polyetheretherketone (PEEK) tubes to the two inlets for injecting two samples and buffer, and the two outlets for collecting and discharging waste (Figure 1).
   2. Manually fill the microfluidic acoustophoresis channel with bubble-free demineralized water using a 10 mL syringe.
   3. Prepare a precision pressure controller with two or more output channels to control the fluid flow. Then, half-fill the vials with sample and buffer, respectively, with two holes in their caps, and connect them to the chip inlet.
      NOTE: A precision pressure contr....

Results

Figure 1: Schematic of the acoustofluidic system used to separate and collect cells. The .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
10 µm Streptavidin-coated microbeads	Bang Laboratories	CP01007	Aptamer affinity beads
Aptamer	Integrated DNA Technologies	GN3-6'	RNA for bacteria conjugation
Escherichia coli DH5α	KCTC	KCTC2571	Target bacteria
Functional generator	GW Instek	AFG-2225	Generate frequency
High-speed camera	Photron	FASTCAM Mini	Observation of separation
KOVAX-SYRINGE 10 mL Syringe	Koreavaccine	22G-10ML	Fill the microfluidic acoustophoresis channel with bubble-free demineralized water.
Microscope	Olympus Corp.	IX-81	Observation of separation
PEEK Tubes	Saint-Gobain Ppl Corp.	AAD04103	Inject or collect particles
Piezoelectric transducer	Fuji Ceramics	C-213	Generate specific wave in channel
Power amplifier	Amplifier Research	75A250A	Amplify frequency
Pressure controller/μflucon	AMED	AMED-μflucon	Control of air pressure/flow controller