The automated liquid handler tends to get the attention, and fairly, since it does the work that gives the field its name. But it almost never works alone. A plate on a modern workcell passes through a surprising number of other devices before it becomes a result, and each of them shapes the sample the liquid handler is trying to move accurately. Knowing the landscape of devices around the liquid handler, and how each one touches your liquid, is part of understanding why a transfer that was accurate yesterday can drift today.
This is a tour of the kinds of devices you find on a workcell, grouped by what they do, and a look at why the peripherals matter to the liquid classes running on the handler in the middle of them.
Grouping the devices
The equipment on a workcell ranges from highly specialized analytical instruments to simple labware movers. It helps to group them by function rather than by vendor.
- Liquid handlers: the devices that move reagents and samples between labware, the ones a liquid class actually governs.
- Analytical and detection devices: plate readers, imagers, sequencers, and mass spectrometers that turn a prepared plate into data.
- Sample conditioning devices: thermocyclers, incubators, shakers, washers, and centrifuges that change the temperature, mixing, or composition of the sample between transfers.
- Labware handling devices: robotic arms, grippers, stackers, and tracks that carry plates from one station to the next.
- Sealing and processing devices: sealers, peelers, de-lidders, and dispensers that prepare labware for storage or the next step.
- Storage devices: hotels, carousels, and incubated stores that hold labware so the cell can run unattended.
Why the peripherals matter to your liquid class
A liquid class assumes a particular state of the liquid and the labware, and the peripherals are what set that state. A thermocycler or an incubator changes the temperature of a sample, and temperature moves viscosity, density, and vapor pressure, so a class validated at room temperature may be wrong on a plate that just came off a heat block. A sealer means the next handler step has to peel before it can aspirate. Time spent waiting in a hotel lets small volumes evaporate. The liquid handler is one device in a chain, and its class is only valid for the sample state the rest of the chain hands it.
Choosing devices that cooperate
A workcell is only as good as the fit between its parts, and that fit is easier to achieve when devices share conventions. Standard labware footprints, the SLAS and ANSI plate dimensions, let an arm move a plate between devices without custom tuning at each one. Standard control interfaces let the scheduler drive a new device without a bespoke integration. When you add a device to a cell, its interoperability matters as much as its individual capability, because a brilliant instrument that does not cooperate with the others buys you a manual step in the middle of an automated run.
The liquid handler moves the liquid, but the devices around it decide what state that liquid is in. A class is only valid for the sample the rest of the cell hands it.