title: Shaping acoustic fields as a toolset for microfluidic manipulations in diagnostic technologies.
abstract: Ultrasonics offers the possibility of developing sophisticated fluid manipulation tools in lab-on-a-chip technologies. Here we demonstrate the ability to shape ultrasonic fields by using phononic lattices, patterned on a disposable chip, to carry out the complex sequence of fluidic manipulations required to detect the rodent malaria parasite Plasmodium berghei in blood. To illustrate the different tools that are available to us, we used acoustic fields to produce the required rotational vortices that mechanically lyse both the red blood cells and the parasitic cells present in a drop of blood. This procedure was followed by the amplification of parasitic genomic sequences using different acoustic fields and frequencies to heat the sample and perform a real-time PCR amplification. The system does not require the use of lytic reagents nor enrichment steps, making it suitable for further integration into lab-on-a-chip point-of-care devices. This acoustic sample preparation and PCR enables us to detect ca. 30 parasites in a microliter-sized blood sample, which is the same order of magnitude in sensitivity as lab-based PCR tests. Unlike other lab-on-a-chip methods, where the sample moves through channels, here we use our ability to shape the acoustic fields in a frequency-dependent manner to provide different analytical functions. The methods also provide a clear route toward the integration of PCR to detect pathogens in a single handheld system.
authors.affiliation: Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Julien
authors.initials: J
authors.lastname: Reboud
authors.forename: Yannyk
authors.initials: Y
authors.lastname: Bourquin
authors.forename: Rab
authors.initials: R
authors.lastname: Wilson
authors.forename: Gurman S
authors.initials: GS
authors.lastname: Pall
authors.forename: Meesbah
authors.initials: M
authors.lastname: Jiwaji
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Pitt
authors.forename: Anne
authors.initials: A
authors.lastname: Graham
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Waters
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Cooper
mesh_terms: D000162:Acoustics; D000818:Animals; D002452:Cell Count; D019937:Diagnostic Techniques and Procedures; D004867:Equipment Design; D004912:Erythrocytes / Q000469:parasitology; D006454:Hemoglobins; D006801:Humans; D008288:Malaria / Q000097:blood / Q000175:diagnosis*; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D044085:Microfluidics; D010962:Plasmodium berghei / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D013499:Surface Properties
chemical_list: D006454:Hemoglobins