Methods for on-demand printing discrete entities including, e.g., cells, media or reagents to substrates are provided. In certain aspects, the methods include manipulating qualities of the entities or biological components thereof. In some embodiments, the methods may be used to create arrays of microenvironments and/or for two and three-dimensional printing of tissues or structures and/or for in situ printing for microsurgeries. Systems and devices for practicing the subject methods are also provided.

Described herein are bioprinters comprising: one or more printer heads, wherein a printer head comprises a means for receiving and holding at least one cartridge, and wherein said cartridge comprises contents selected from one or more of: bio-ink and support material; a means for calibrating the position of at least one cartridge; and a means for dispensing the contents of at least one cartridge. Further described herein are methods for fabricating a tissue construct, comprising: a computer module receiving input of a visual representation of a desired tissue construct; a computer module generating a series of commands, wherein the commands are based on the visual representation and are readable by a bioprinter; a computer module providing the series of commands to a bioprinter; and the bioprinter depositing bio-ink and support material according to the commands to form a construct with a defined geometry.

Disclosed herein is a system to detect and characterize individual particles and cells using at least either optic or electric detection as the particle or cell flows through a microfluidic channel. The system also provides for sorting particles and cells or isolating individual particles and cells.

Described herein are bioprinters comprising: one or more printer heads, wherein a printer head comprises a means for receiving and holding at least one cartridge, and wherein said cartridge comprises contents selected from one or more of: bio-ink and support material; a means for calibrating the position of at least one cartridge; and a means for dispensing the contents of at least one cartridge. Further described herein are methods for fabricating a tissue construct, comprising: a computer module receiving input of a visual representation of a desired tissue construct; a computer module generating a series of commands, wherein the commands are based on the visual representation and are readable by a bioprinter; a computer module providing the series of commands to a bioprinter; and the bioprinter depositing bio-ink and support material according to the commands to form a construct with a defined geometry.

A nozzle plate of a fluid ejection head for a fluid ejection device, a fluid ejection head containing the nozzle plate, and a method for making the fluid ejection head containing the nozzle plate. The nozzle plate contains two or more arrays of nozzle holes therein and a barrier structure disposed on an exposed surface of the nozzle plate between adjacent arrays of nozzle holes, wherein the barrier structure deters cross-contamination of fluids between the adjacent arrays of nozzle holes.

A pipette-fillable fluid reservoir body. The fluid reservoir body includes two or more discrete fluid chambers therein. At least one of the fluid chambers contains a pressure compensation device and at least another one of the fluid chambers is devoid of a pressure compensation device. Each of the fluid chambers is in fluid flow communication with a fluid supply via, and each of the fluid chambers have sidewalls and a bottom wall attached to the side walls, wherein the bottom wall slopes toward the fluid supply via. The fluid reservoir body also includes an ejection head support face in fluid flow communication with the fluid chambers for attachment of a fluid ejection device to the ejection head support face for ejecting fluid from the fluid chambers.

The present disclosure provides apparatuses, systems, and methods involving a spotter apparatus for depositing a substance from a carrier fluid onto a deposition surface in an ordered array, the spotter apparatus comprising a loading surface including a first well and a second well; and a different outlet surface, including a first opening and a second opening, where a first microconduit fluidly couples the first well with the first opening and a second microconduit fluidly couples the second well with the second opening. An overlay is sealed to the outlet surface and penetrated by a deposition channel that is situated to communicate carrier fluid among the first opening, the second opening, and the deposition surface when the overlay is pressed against the deposition surface.

Devices and methods for characterization of analyte mixtures are provided. Some methods described herein include performing enrichment steps on a device before expelling enriched analyte fractions from the device for subsequent analysis. Also included are devices for performing these enrichment steps.

An apparatus for sequencing a polynucleotide analyte is provided and comprises; •a first zone in which a stream of single nucleotides is generated by progressive digestion of a molecule of the analyte attached to a particle located therein and exposed to a flowing aqueous medium; •a second zone in which a corresponding stream of aqueous droplets is generated from the aqueous medium and the nucleotide stream and wherein at least some of the droplets contain a single nucleotide and •a third zone in which each droplet is stored and/or interrogated to reveal a property characteristic of the single nucleotide it may contain; characterised in that the first zone comprises a microfluidic channel through which the aqueous medium flows and the location comprises a hollow seating in a wall thereof to which suction can be applied and into which the particle can be close-fitted.

This invention relates to methods, systems, and computer program products for verifying dispensing of a fluid from a pipette.