Instruments
Pipetting on 96- and 384-channel heads: full, partial, and per-channel
A 96-channel head is not 96 independent pipettes. What changes when one plunger drives many tips, and how partial pickup and per-channel work differ.
Liquid handling, liquid classes, and the craft of accurate pipetting
Practical guides to calibrating, versioning, and trusting the liquid classes that drive your automated liquid handlers. Written for the people who run the deck.
- Compliance
Data integrity for pipetting runs: what 21 CFR Part 11 and GxP actually ask for
A plain-language guide to attributable, legible, contemporaneous records for automated liquid handling, and why your liquid class is part of the audit trail.
- Best practices
Troubleshooting a liquid handler: reading symptoms back to parameters
Most pipetting faults show before you measure. Read dripping, bubbles, short fills, and carryover back to the property and the one parameter that fixes each.
- Instruments
Anatomy of a workcell: the integrated system your liquid classes run inside
A workcell turns a set of instruments into one system. Its parts, the scheduler that coordinates them, and where the method layer sits once the handler is one device among many.
- Instruments
Automation architecture: centralized method services versus per-instrument silos
The architecture of an automated lab is decided early and lived with. Monolithic vs modular, centralized vs distributed, and why where your liquid classes live is a structural choice too.
- Instruments
Device drivers: the control-layer problem behind method portability
Drivers are the software that lets a scheduler control an instrument, and they are notoriously hard. Why they matter, why they break, and how the method layer inherits their fragility.
- Instruments
The lab automation device landscape: the peripherals around the liquid handler
The liquid handler shares a workcell with readers, thermocyclers, movers, and sealers. A tour of the device landscape and why each peripheral changes the sample your liquid class assumes.
- Technique
Transferring a liquid class between instruments and sites without starting over
A calibration is tied to the hardware it was built on. Here is how to move a liquid class to another instrument or lab and prove it still delivers.
- Technique
Touch-off: shedding the last drop against the well
A hanging droplet is delivered volume that never left the tip. How a touch-off against the well wall finishes a dispense, and when it helps or hurts.
- Applications
Automating ELISA: the liquid-handling settings that protect reproducibility
ELISA lives or dies on even, gentle, well-timed liquid handling. Here are the dispense, wash, and reagent-addition settings that keep plates consistent.
- Best practices
In-line volume verification: checking the run, not just the class
Validating a class proves it worked once. In-line verification checks volumes during the run itself, catching the failures offline testing never sees.
- Best practices
The standards behind automated liquid handling: ISO 8655, ANSI/SLAS, and why they matter
A tour of the standards that make pipetting comparable across labs and instruments, from volumetric accuracy to the microplate footprint your deck depends on.
- Technique
Automating cell culture: gentle liquid handling for living samples
Cells are not just another liquid. Media changes and washes need low shear and careful aspiration heights so the monolayer or pellet survives the transfer.
- Compliance
Qualifying a liquid class for a regulated lab: IQ, OQ, and PQ in plain terms
Installation, operational, and performance qualification explained for liquid handling, and how a validated liquid class fits into the evidence you keep.
- Best practices
Connecting a liquid handler to a LIMS: where classes meet sample data
A liquid handler moves samples; a LIMS knows what they are. Linking the two turns a worklist into a tracked result rather than a plate of anonymous wells.
- Compliance
Change control for liquid classes: how a new version gets reviewed and approved
Changing a calibration that produces reported data is a governed act, not a quick edit. Here is a sane change-control flow for liquid classes.
- Best practices
Barcode tracking and sample identity in an automated run
Automation only scales if the robot knows which sample is which. How barcodes, autoloaders, and positional tracking keep identity attached to every well.
- Applications
Sample prep for LC-MS/MS: precise transfers where small volumes decide the result
Mass spec quantitation is only as good as the standards and dilutions feeding it. Here is how to keep low-volume transfers accurate for LC-MS/MS.
- Instruments
Moving labware on the deck: grippers, plate handlers, and collisions
Before a tip touches liquid, something has to move the plate. How gripper arms relocate labware, and why deck geometry and collisions decide whether it works.
- Applications
NGS library prep on a liquid handler: small volumes, tight ratios, unforgiving error budgets
Library prep stacks dozens of small, ratio-sensitive transfers. Here is how to automate it without letting pipetting error compound into failed libraries.
- Technique
Liquid level detection: how the tip knows where the surface is
Capacitive and pressure-based level detection let a liquid handler follow the meniscus, submerge just enough, and catch clots or empty wells. Here is how each works.
- Best practices
Build vs. buy: should you write your own liquid classes or adopt a shared catalog?
Every lab decides whether to develop liquid classes in-house or start from a shared catalog. Here is an honest look at the real costs of each.
- Fundamentals
Liquid class principles: mechanisms, liquid types, and dispense functions
A working mental model for liquid classes: the transfer mechanism you are on, the three liquid types, and the wet, free, and mix dispenses that shape every parameter.
- Technique
Tip waste and disposal: the unglamorous end of a transfer
A transfer is not finished until the tip is gone. How tip ejection and waste routines fail quietly, and why they matter to carryover and run reliability.
- Best practices
Reproducibility across labs: why sharing the definition is not the same as sharing the result
Two labs can run the identical liquid class and get different volumes. Here is what a shared definition leaves out, and how to close the gap.
- Best practices
Validating a liquid class: gravimetric calibration, step by step
A liquid class is a hypothesis until you weigh it. How to verify accuracy and precision gravimetrically, adjust with a calibration curve, and re-check over time.
- Best practices
The real cost of a miscalibrated liquid class: rework, reagents, and risk
A slightly wrong liquid class rarely fails loudly. It leaks cost through wasted reagents, repeated runs, and decisions made on quietly bad data.
- Instruments
Types of liquid handlers: heads, decks, and dispensing mechanisms
Stamping versus independent-channel heads, the deck as both grid and control surface, and the acoustic, peristaltic, and plate-washing devices that round out a lab.
- Instruments
Preventive maintenance for syringe pumps: a three-point check that prevents bad data
The syringe pump is where a liquid handler turns motion into volume. A simple routine of seals, valves, and system liquid keeps it honest.
- Fundamentals
What is a liquid class, and why it decides your pipetting accuracy
A liquid class is the parameter set that tells an automated liquid handler how to aspirate and dispense a specific liquid. Here is what lives inside one and why it matters.
- Instruments
Pressure sensors and real-time monitoring: catching a bad aspiration as it happens
A pressure trace turns pipetting from a blind command into an observed event, letting a liquid handler flag a clot, a bubble, or an empty well mid-run.
- Fundamentals
Reading the parameters: a vendor-neutral liquid-class glossary
Flow rate, air transport volume, blowout, swap speed, settling time and more, decoded, with the names each vendor uses so a class reads the same everywhere.
- Instruments
Interoperability and SiLA: getting instruments from different vendors to speak one language
A modern lab mixes instruments from many vendors. Standards like SiLA and a vendor-neutral view of liquid classes are how they cooperate instead of siloing.
- Technique
Dispense modes: free, contact-wet, and contact-dry, and when to use each
Whether the tip free-falls the liquid, touches a wet well, or touches a dry surface changes accuracy, contamination risk, and speed. A practical guide to the three modes.
- Fundamentals
The physics behind a liquid class: the properties that decide your parameters
Viscosity, density, surface tension, contact angle, vapor pressure and more each push specific liquid-class parameters. A tour of the properties that make a class.
- Fundamentals
Air displacement, positive displacement, and the role of system liquid
Disposable tips with an air cushion or fixed tips backed by system liquid: the two fluidic architectures behind liquid handlers, and how each shapes your classes.
- Fundamentals
Choosing a starting liquid class: liquid families and their synonyms
The fastest new class starts from an existing one for a similar liquid. How to group liquids into families and pick the closest predefined class to adapt.
- Fundamentals
Accuracy vs precision in pipetting, and which parameters fix each
A biased class and a noisy class fail in different ways and call for different fixes. How to tell accuracy from precision and map each to specific liquid-class settings.
- Best practices
From default to validated: the liquid class development workflow
A five-step routine for building a class: understand the liquid, start from a predefined class, inspect, change one parameter at a time, then verify with a correction curve.
- Technique
Choosing tips for your liquid class: geometry, coatings, and fit
Tip volume range, filtered, conductive, wide-bore, and low-retention options all change how a liquid behaves. Why the tip is part of the class, not an accessory.
- Technique
Environmental drift: how the room changes your pipetting
Temperature, humidity, air pressure and vibration all shift how a liquid behaves. Why you develop classes at normal lab conditions, record them, and re-check on change.
- Instruments
Pump and syringe selection: how the fluidic path caps your liquid class
Syringe size sets the trade between volume range and resolution, and the pump and tubing bound what any liquid class can achieve. A primer for anyone specifying a system.
- Technique
Correction curves, explained
A correction curve maps target volume to what the instrument must aim for, so the delivered volume is right across the whole range and not just at one point.
- Technique
How to pipette viscous liquids without losing volume
Glycerol, DMSO, and detergents defeat default settings. A practical guide to flow rates, delays, and air gaps for accurate automated handling of viscous liquids.
- Technique
Writing a liquid handling protocol: code vs visual designers
A protocol is where liquid classes meet the deck. Scripted Python and visual designers each have strengths for reproducibility and reuse, and the class fits into both.
- Best practices
Serial dilution without carryover
Serial dilutions multiply small errors and invite carryover. Fresh tips, thorough mixing, sensible mix volumes, and dropping the over-aspirate keep a series honest.
- Best practices
Dry-running a protocol: simulation before the deck
Most protocol failures are catchable before the robot moves. How simulation and deck visualization surface collisions, shortfalls, and labware mistakes offline.
- Fundamentals
Porting a method across vendors: what a liquid class carries
Moving a protocol between Opentrons, Hamilton, and Tecan is rarely copy-and-paste. Which parts of a liquid class translate, which must be re-tuned, and how to plan the move.
- Best practices
Multi-dispensing done right
Aliquoting one aspiration into many wells is fast but tricky. When to use it, why to discard the first and last aliquots, and how to correct a step-down volume series.
- Fundamentals
AI in the automated lab: why liquid classes are the ground truth
AI can draft a protocol from a sentence, but it cannot invent how a liquid behaves in a tip. Why validated, machine-readable liquid classes keep automated intelligence honest.
- Technique
Pipetting low volumes on large channels
Dispensing 0.5 to 20 microliters on 1000 microliter channels is where errors hide. Smaller tips, surface dispensing, and turning off liquid following keep it honest.
- Best practices
Compliance and audit readiness for automated liquid handling
In regulated labs a transfer is not done until it is documented. Audit trails, electronic signatures, and change control for methods and the liquid classes behind them.
- Best practices
How to measure a transfer: photometric, fluorometric, gravimetric
You cannot trust a volume you have not measured. The three quantitative methods, photometric, fluorometric, and gravimetric, and when each is the right tool.
- Fundamentals
Open and shareable liquid handling: reproducibility beyond your own lab
A result no one else can reproduce is a fragile result. Why open protocols and shared, inspectable liquid classes make automated science more reproducible.
- Instruments
Labware definitions and deck layout: the accuracy factors you set once
An instrument only knows the deck you describe to it. Why accurate labware definitions and offsets underpin correct heights, level detection, and every transfer on top.
- Best practices
Versioning liquid classes: why provenance beats a shared drive
Undocumented parameter tweaks are how methods silently drift. How versioning and provenance turn liquid classes into trustworthy, auditable lab assets.
- Best practices
Trueness, precision, and the ISO vocabulary
The industry standardized what accuracy means for liquid handlers. Trueness, precision, and accuracy defined, the percent-error and percent-CV formulas, and the ISO documents behind them.
- Fundamentals
When to automate: manual, semi-automated, or full automation
More automation is not always the answer. A practical way to weigh sample count, throughput, reproducibility, dead volume, labor, and safety before you commit.
- Technique
Air gaps and blowout: the small settings that stop dripping and carryover
Air gaps and blowout volume are the most misunderstood liquid class parameters. What each one does, when to use it, and how they prevent dripping and carryover.