Automated pipetting system using manual pipettes

A liquid handling robot is used to automate workflows in life science laboratories. It is a

robot A robot is a machine—especially one programmable by a computer—capable of carrying out a complex series of actions automatically. A robot can be guided by an external control device, or the control may be embedded within. Robots may be ...

that dispenses a selected quantity of reagent, samples or other liquid to a designated container.

Introduction

Liquid handling plays a pivotal role in life science laboratories. The sample volumes are usually small, at the micro- or nanoliter level, and the number of transferred samples can be huge. Under these conditions, liquid handling by hand is tedious, time-consuming, and impractical. Consequently, there is a strong demand for automated liquid handling robots.

Types of liquid handling robots

The simplest version simply dispenses an allotted

volume Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). Th ...

of liquid from a motorized

pipette A pipette (sometimes spelled as pipett) is a laboratory tool commonly used in chemistry, biology and medicine to transport a measured volume of liquid, often as a media dispenser. Pipettes come in several designs for various purposes with dif ...

syringe A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside o ...

; more complicated machines can also manipulate the position of the dispensers and containers (often a Cartesian coordinate robot, such as th
XYZ Triton Robot
from TriContinent Scientific) and/or integrate additional laboratory devices, such as centrifuges, microplate readers, heat sealers, heater/shakers, bar code readers, spectrophotometric devices, storage devices and incubators. More complex liquid handling workstations can perform multiple Laboratory Unit Operations such as sample transport, sample mixing, manipulation and incubation, as well as transporting vessels to/from other workstations. They can range from a specialized bench-top 8-channel DNA PCR processing robot, to a customized-for-process automated liquid handling system, such as the

TECAN Tecan Group Ltd. is a Swiss company providing laboratory instruments and solutions in biopharmaceuticals, forensics, and clinical diagnostics for pharmaceutical and biotechnology companies, university research departments and diagnostic labor ...

Freedom EVO (shown on the right), the HighRes Biosolution's PRIME and Janus Automated liquid handlers from

PerkinElmer PerkinElmer, Inc., previously styled Perkin-Elmer, is an American global corporation focused in the business areas of diagnostics, life science research, food, environmental and industrial testing. Its capabilities include detection, imaging, in ...

. Other liquid handling systems are designed for specific experiments, e.g. the Intavis InsituPro robot for the automation of

immunohistochemistry Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to a ...

and

in situ hybridization ''In situ'' hybridization (ISH) is a type of hybridization that uses a labeled complementary DNA, RNA or modified nucleic acids strand (i.e., probe) to localize a specific DNA or RNA sequence in a portion or section of tissue (''in situ'') or ...

on whole-mounts and slides. An alternative category of liquid handlers mimics the operations of humans, by performing liquid transfers as humans would do. These robots achieve the cartesian, 3-axis movements implemented in larger workstations, by means of an arm. In some cases (like the "Andrew" system or ASSIST PLUS robot shown on the right) they can even use the same pipettes and consumables as humans.

Modularity

Liquid handling robots can be customized using different add-on modules such as

centrifuges A centrifuge is a device that uses centrifugal force to separate various components of a fluid. This is achieved by spinning the fluid at high speed within a container, thereby separating fluids of different densities (e.g. cream from milk) or ...

, PCR machines, colony pickers, shaking modules, heating modules and others. Some liquid handling robots utilize Acoustic Liquid Handling (also known as acoustic droplet ejection or ADE) which uses sound to move liquids without the traditional pipette or syringe.

Control Software

Control software, either on a connected computer, or integrated into the system itself, allows the user to customize the liquid handling procedures and transfer volumes.

Quality Control

One of the challenges in using automated liquid handlers, or liquid handling robots, is in verifying the proper function of the device. Liquid handling operations, performed by these automated systems, can fail due to clogged pipette tips, failed solenoid valves, damaged labware, operator error and many other reasons. A variety of methods exist for performing quality control of liquid dispensing on automated platforms including gravimetric, fluorescent and colorimetric measurements. In addition to manual quality control methods, technologies have been developed which allow for the automated monitoring of quality control of liquid handling robots.

References

{{reflist Robotic manipulation