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In electrophoresis, the migration velocity is used for sizing DNA and proteins or for distinguishing molecules based on charge and hydrodynamic radius. Many protein and DNA assays relevant to disease diagnosis are based on such separations. However, standard protocols are not only slow (minutes to hours) but also insensitive (many molecules in a detectable band). We successfully demonstrated a high-throughput imaging approach that allows determination of the individual electrophoretic mobilities of many molecules at a time. Each measurement only requires a few milliseconds to complete. This opens up the possibility of screening single copies of DNA or proteins within single biological cells for disease markers without performing polymerase chain reaction or other biological amplification. The purpose is not to separate the DNA molecules but to identify each one on the basis of the measured electrophoretic mobility. We developed three different procedures to measure the individual molecular mobilities. The results correlate well with capillary electrophoresis (CE) experiments for the same samples (2-49 kb dsDNA) under identical separation conditions. The implication is that any electrophoresis protocols from slab gels to CE should be adaptable to single-molecule screening for disease diagnosis.

Medium excitation by jet shower propagation inside a quark-gluon plasma is studied within a linear Boltzmann transport and a multiphase transport model. Contrary to the naive expectation, it is the deflection of both the jet shower and the Mach-cone-like excitation in an expanding medium that is found to gives rise to a double-peak azimuthal particle distribution with respect to the initial jet direction. Such deflection is the strongest for hadron-triggered jets which are often produced close to the surface of dense medium due to trigger-bias and travel against or tangential to the radial flow. Without such trigger bias, the effect of deflection on γ-jet showers and their medium excitation is weaker. Comparative study of hadron and γ-triggered particle correlations can therefore reveal the dynamics of jet-induced medium excitation in high-energy heavy-ion collisions.PACS numbers: 25.75.Bh,25.75.Cj,25.75.Ld Strong jet quenching has been observed in experiments [1][2][3][4] at the Relativistic Heavy-ion Collider (RHIC) as a consequence of jet quenching or parton energy loss in high-energy heavy-ion collisions [5]. The energy and momentum lost by a propagating parton will be carried by radiated gluons and recoiled medium partons which in turn will go through further interaction and eventually lead to collective medium excitation such as supersonic waves or Mach cones [6,7]. Indeed, Mach cones have been found in the solutions of both hydrodynamic response [8][9][10][11][12] and linearized Einstein equations in string theory [13,14] excited by a propagating jet. Such collective excitation by a propagating jet is expected to be responsible for the observed conic back-to-back (b2b) azimuthal dihadron [15,16] and trihadron correlations [17] with a maximum opening angle of ∆φ ≈ 1 (rad) relative to the backside of a triggered high-p T hadron. However, hadron spectra from the freeze-out of the Mach cone in both hydrodynamics with realistic energy-momentum deposition by jets [6,9,10] and string calculations in the hydrodynamic regime [14] fail to reproduce the observed conic azimuthal correlations. Such correlations on the other hand are observed in a multiphase transport (AMPT) Monte Carlo simulations [18] which could come from jetinduced wakes that are deflected by a radially expanding medium [10].Dihadrons with a high-p T trigger are mostly dominated by b2b jets that are produced close to the surface of the dense matter [19] with the awayside jets often traveling against or tangential to the radial flow. Deflection of these jet showers and associated Mach cones by the radial flow can lead to double-peaked hadron azimuthal correlations. On the other hand, high-p T γ's are produced throughout the volume of the dense matter [20]. The effect of deflection should be reduced for γ-triggered jet showers after averaging over all possible production positions and propagation direction, leading to a weaker double-hump γ-hadron correlation as compared to dihadron correlation.In this Letter, we will study medium excitation by a...