Have you ever tried to use any of the IKEA software that help their costumer configure their own furniture? Get the optimal configuration for your application is more or less the same than buying your personalized closet from the Swedish furniture company: lots of options, modules and components, each one with different functionalities that you have to fit in a limited space and usually limited budget. Getting to know the basic components and how to combine them usually is the 1st challenge of liquid handling automation.
Here are some general guidelines to compare effectively the most common options current liquid handlers offer and the benefits and handicaps of each one:
As IKEA closets do, configurable liquid handlers came in different sizes, but rather than meters, it is better to measure and compare the capacity in SBS positions. Standard platforms range from 12 to 50 SBS positions. Bigger systems will have loger walk-away time and will allow implementing more and more applications in the future without disturbing previous methods or changing deck components from one protocol to another.
Because bigger means more expensive. The perfect size for a specific need is usually given by a compromise between functionality (“I want to fit all my clothes in the closet”) and budget ( “If I can fit everything in a smaller one, more money to buy other stuff”)
In this area there are Mainly 3 options,
8-multichannel tools are simple, fast and reliable tools when working with SBS microtiter plates. All channels aspirate the same volume at the same time and the separation within channels is given to allow working with single columns of a 96 plate. The simplicity of this tool makes them ideal for an entry-level liquid handler system.
These pipetting heads can’t work with single tubes, so usually there they offer a smart solution to include a single channel option. Just two examples of that: Tecan’s EVO75 8 Plus 1 approach allows 1 channel to be independent of the rest. Instead Beckman’s Biomek 4000 simply interchanges automatically the multichannel head with a single channel one. Although these solutions are functional, they increase the processing time when many reformatting steps are required.
The most extended tool due to its performance/cost ratio: same speed as 8 multichannel tool when filling a plate, excellent performance when cherry-picking, and extremely useful in applications when different aspiration/dispensation volumes are (concentration normalization steps).
Although some manufacturers like Hamilton Robotics offers the possibility to have up to 16 independent channels, most common and desirable configurations are 8 channels, or 4 if the budget is limited.
Nowadays 2 pipetting technologies coexist, positive displacement channels and liquid based (syringes) one. Most of the robotics community seem to agree that positive displacement channels offer several benefits over the syringe systems, such as wider pipetting range which means more flexibility, fewer maintenance routines and reduction of contamination risk.
96/384 Multichannel Heads.
This massive pipetting heads are able to transfer 96 or 384 samples in seconds , they share the same limitations with the above mentioned 8 multichannels systems, so they lack the ability work efficiently with tubes; but their high throughput make them a wonderful choice when working only with samples on plates. Among the benefits of 96 multichannel head are the reduction of the processing time and bias reduction due to the sample position within the well. All samples in the whole plate are induced, purified, mixed or incubate simultaneously. The price to pay for these high speed pipetting tools is not measured only with money, these systems require a tremendous amount of space due to the fact that all reservoirs must use a full SBS position and a full rack of 96 tips available to use them.
Experienced users will use this tool wisely both as a 8 and a 96 multichannel head, saving tips and space in non-critical steps, this can be achieved by using special SBS reservoirs and partial tip loading capabilities, allowing the head to work only with one row or one columns of tips.
Dual Hybrid configurations 8/96:
For many the “ultimate platform”, is like having a full dressing room instead of just a closet. They combine unsurpassed flexibility and throughput by having both independent channels and a 96 multiprobe head. Of course having 2 tools means you will have to pay more to have them, the only problem of this configurations (just to say one) is that they will split your deck in 3 parts (2 of them on the sides that will be only accessible with one tool or another, and a middle section that will be accessed with both)
At this point the rest of the characteristics are mostly brand-dependent and will not be discussed to simplify the matter. Anyways feel free to leave your impressions or even start a debate on the forum section of labautomation.com
IKEA & the Liquid Handlers: How to find the right configuration for the right application