Abstract: Provided herein are microfluidic viscometer assemblies and methods using the same, that include a microfluidic cartridge having microfluidic circuits that have channels adapted for viscosity determination without the need of a control fluid or oil. The viscometer assemblies also include an image recording system and a pressure control unit. In some embodiments, a temperature control unit is included as well. During methods using the viscometers provided herein, microfluidic cartridges can be loaded and removed from a viscometer, and disposed of.

Abstract: Various embodiments of fluidic devices and methods of the present teaching can provide precision on-device loading of fluidic samples, and merging, mixing, and splitting of the fluidic samples, in illustrative embodiments as droplets, using pressures that can be provided by standard laboratory liquid handling equipment. Various embodiments of fluidic devices of the present teachings can provide on-device manipulation of accurate and precise fluidic volumes at the picoliter to nanoliter scale for each steps from fluidic sample loading to fluidic sample splitting. Various embodiments of fluidic elements of the present teachings, for example, but not limited by, various embodiments of fluidic traps of the present teachings, can have a constrained and measurable geometry, allowing for accurate and precise tuning of each fluidic sample volume throughout the on-device liquid handling process.

Abstract: This disclosure provides fluidic devices and methods for performing a bioassay, for example bioassays performed on zebrafish. The disclosure provides various fluidic devices for performing a bioassay that include a sample chamber in fluid communication with an air valve; and a bioassay channel that can include a first bioassay region, for example for studying zebrafish in early stages of development and a second bioassay region, for studying zebrafish in later stages of development. The first bioassay region and second bioassay region can be defined using pillars, such as a first and second array of pillars. The fluidic device can have additional structures that are provided herein. Also provided herein are sample loading manifold devices for loading zebrafish embryos into fluidic devices and reagent delivery manifold devices for delivering reagents to fluidic devices. Furthermore, methods using any or all of the devices are provided.

Abstract: The present disclosure provides fluidic devices that in some embodiments have passive air control valves and in some instances, high resistance air valve constriction channels, or channel dimensions and compositions that provide effective capillary pressure ratios, that can be used to fill reaction wells and/or manipulate fluids in reaction wells. Also provided are fluidic systems containing fluidic devices adjoined to one another, methods for operating the fluidic devices, and methods for manipulating fluids using the fluidic devices. Methods for use of the fluidic devices in performing immunoassays, nucleic acid detection, other assay systems, including but not limited to point of care applications are also provided.