title: Chemical-free lysis and fractionation of cells by use of surface acoustic waves for sensitive protein assays.
abstract: We exploit the mechanical action of surface acoustic waves (SAW) to differentially lyse human cancer cells in a chemical-free manner. The extent to which cells were disrupted is reported for a range of SAW parameters, and we show that the presence of 10 μm polystyrene beads is required to fully rupture cells and their nuclei. We show that SAW is capable of subcellular fractionation through the chemical-free isolation of nuclei from whole cells. The concentration of protein was assessed in lysates with a sensitive microfluidic antibody capture (MAC) chip. An antibody-based sandwich assay in a microfluidic microarray format was used to detect unlabeled human tumor suppressor protein p53 in crude lysates, without any purification step, with single-molecule resolution. The results are digital, enabling sensitive quantification of proteins with a dynamic range >4 orders of magnitude. For the conditions used, the efficiency of SAW-induced mechanical lysis was determined to be 12.9% ± 0.7% of that for conventional detergent-based lysis in yielding detectable protein. A range of possible loss mechanisms that could lead to the drop in protein yield are discussed. Our results show that the methods described here are amenable to an integrated point-of-care device for the assessment of tumor protein expression in fine needle aspirate biopsies.
authors.affiliation: The Proxomics Project and §Institute of Chemical Biology, Department of Chemistry, Imperial College London , London SW7 2AZ, United Kingdom.
authors.forename: Ali
authors.initials: A
authors.lastname: Salehi-Reyhani
authors.forename: Frank
authors.initials: F
authors.lastname: Gesellchen
authors.forename: Dileep
authors.initials: D
authors.lastname: Mampallil
authors.forename: Rab
authors.initials: R
authors.lastname: Wilson
authors.forename: Julien
authors.initials: J
authors.lastname: Reboud
authors.forename: Oscar
authors.initials: O
authors.lastname: Ces
authors.forename: Keith R
authors.initials: KR
authors.lastname: Willison
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Cooper
authors.forename: David R
authors.initials: DR
authors.lastname: Klug
mesh_terms: D002458:Cell Fractionation / Q000295:instrumentation*; D045744:Cell Line, Tumor; D004867:Equipment Design; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D013016:Sound; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
chemical_list: D016159:Tumor Suppressor Protein p53