Abstract: Provided herein are various examples of a method of coupling oligonucleotides to a polymer. The method may include selectively irradiating first inactive moieties in a one or more first region of a polymer with light, while not irradiating second inactive moieties in a one or more second region of the polymer, to generate first active moieties in the one or more first region of the polymer. The method may also include coupling the first active moieties to first oligonucleotides. The method may further include irradiating the second inactive moieties in the one or more second region of the polymer with light to generate second active moieties in the one or more second region of the polymer. The method may also include coupling the second active moieties to second oligonucleotides.

Abstract: Provided are methods and systems that characterize a property of a particle suspended in a fluid sample in a label-free manner. Detection elements are provided fluidically adjacent upstream and downstream from a modulation element. Fluid sample containing particles flows across a first detection element and a first particle parameter detected for each particle that passes the first detection element or a first aggregate particle parameter for a plurality of particles that pass the first detection element. The particles flow from the first detection element to a first modulation element, wherein the first modulation element effects a change in a property of the particles flowing past the first modulation element. A second detection element then detects the particle parameter again or a second aggregate particle parameter for a plurality of particles that pass the second detection element. Comparing the first and second particle or aggregate parameters thereby characterizes the particle property.