Pipette Types: Everything you need to know about multichannel options
Sep 26, 2017
Are you in the market for a multichannel pipette, but not sure where to start? You are in the right place!
In this the second of a two-part series, we are going to examine multichannel pipettes and help you navigate through the options, so that you can come out a purchasing hero. Multichannel pipettes come in different varieties. Common setups are 8 or 12 channels, but they can come in larger channel sets which we will discuss further below.
As we found in the previous article, there are many options to consider. Our goal is to help give you the tools to find the best pipette for your lab. Remember, a pipette purchase may seem small, but the reality is that it is a huge investment for your data quality and for your users. As we stated in the single channel guide, finding the right one is critical.
Let’s start with exploring some background information about multichannel pipettes. A multichannel pipette may be the right one for you if your source and destination containers are larger or have wider surface areas such as troughs, reservoirs or 96-/384-well plates. You can aspirate and dispense into smaller containers like twist top or flip cap tubes, but it will only mean loading one tip at a time onto the pipette, which can introduce quality concerns or handling concerns if the tip is not seated or the pipette is not handled correctly. Having the ability to use multiple channels to aspirate/dispense can increase productivity and reduce ergonomic concerns, because you can aspirate/dispense more at a time when compared to a single channel pipette.
We are not going to focus on any specific brands in this piece as that will be up to you to decide. However, we will go over pipette types, considerations, and budgeting. Let’s get started!
Many of the same questions we investigated and information we discussed for single channel pipettes also apply to multichannel pipettes. Here’s a quick recap of what we discussed in the previous article (in italics) along with some new considerations specific for multichannel pipettes:
1. What kind of liquids are you going to be transferring?
The type of liquid is important regarding the accuracy of the transfer (including user technique). However, note that most multichannel pipettes are air displacement models so you will want to take your liquid type into close consideration to make sure that this pipette type is the best for your application. You may also want to consider whether the tip you will be using needs to be filtered. See #6 below for more information regarding tip types.
2. What about adjustable volume or a fixed volume pipette?
This will depend on how you are going to use the pipette. Fixed volume options should be considered if the adjustable pipette option doesn’t meet your accuracy specification for the desired volume. Adjustable volume pipettes vary in accuracy across their volume range, with the highest accuracy at the high-end and the lowest for the low volumes in the range. Fixed volume pipette models are always going to be adjusted for the highest accuracy at the one set volume If you need to use the pipette for multiple applications, then an adjustable volume model may be the best for you.
3. What about different channel options?
There are a different channel options, meaning different numbers of channels. Just what are your options? See Figure 1 below.
4. Do you need a manual or an electronic pipette?
There are both manual and electronic multichannel pipette options. Using a manual multichannel pipette to do repeat sequential transfers can introduce ergonomic concerns. An example would be transferring samples between 96 well plates and completing this task for multiple plates. As you can imagine the pipetting strain can add up, even though you have the advantage of pipetting multiple channels at the same time. An electronic multichannel can cut down on the strain as you could complete multiple transfers with the push of a button. Just as it was with single channel pipettes, this will depend on the volumes and tip sizes. Again, cost will need to be a consideration as electronic pipettes will likely be more expensive when compared to manual pipettes.
5. What kind of budget do you have to work with for the initial purchase, and for ongoing repair and maintenance?
As we discussed in the previous article there are pros and cons to purchasing new vs. refurbished. You will have to evaluate what kind of warranty or guarantee you want along with the overall cost whether you purchase a new pipette or a refurbished one. One difference regarding repairs is that you have multiple channels to consider instead of just one. That means the potential for purchasing more repair parts, including routine parts like O-rings.
6. Do you plan on using the same pipette tips you currently have in stock and are using, or are you prepared to evaluate and invest in new pipette tips?
This will be something you want to discuss with the vendor. The pipette may function differently with “universal fit” tips vs. manufacturer specific branded tips. Keep in mind that, instead of seating one tip correctly (single channel), there are now multiple (i.e. 8 or 12) tips to seat and ensuring there is a tight seal and smooth ejection will be even more critical than with a single channel pipette. As we stated in the previous article, seating tips improperly and having excessive ejection force can cause damage., not to mention some ergonomic strain. Again, you will want to keep potential repair costs in mind. Having multiple channels instead of one can mean that repairs could add up. So, being proactive and talking to the vendor about recommended tips could save you some costs and lost time down the road. See Figure 2 below for some helpful pipette tip volume considerations, especially when you take filters in your tips into account. The filter can help provide an increased barrier between the pipette and the sample, therefore decreasing contamination events. If you are pipetting volatile or viscous chemicals or samples such as DNA, a filtered tip may be a good option to consider.
Once you have a brand and model in mind, it is a good idea to contact the vendor to ask questions about the pipette. Especially regarding maintenance, calibration, and warranty/coverage. Calibration recommendations and/or requirements would be especially valuable to discuss – more channels to calibrate means more time needed. Empowering yourself with knowledge up front may save you time later. In addition to these questions, you may also want to ask the vendor if they have any kind of ergonomic or comfort rating associated with the pipette. It may provide a useful metric if you are comparing/contrasting models.
7. Have you discussed your purchase with laboratory personnel? Do they have requirements or recommendations?
Having hands on practice may be of benefit since multichannel pipettes have a different feel as compared to single channel pipettes. You may want to ask the vendor for a demonstration to your team to ensure all lab personnel have an opportunity to see just how the pipette “feels”. Having a chance to hold and use the pipette, will give you firsthand experience of the handling ergonomics. If not used properly or with the appropriate tips, the multichannel could become more of an ergonomic problem than a solution.
8. Have you considered the maintenance and repair costs associated with the multichannel pipette you are choosing from?
Recommended maintenance and repair costs can vary significantly among manufactures, and even among models. You may want to inquire with the manufacturer when investigating your purchase options regarding the recommended maintenance and potential repair costs, how long the manufactures warranty is and what it covers. An especially savvy customer would be aware that not all manufacturers have equally easily serviceable multichannel pipettes. With regards to the manifold, some are not repairable, then if 1 channel is damaged, you may have to replace the entire manifold which can be pricey. Some manufactures sell replacements for the individual channels and even make it user-serviceable. These are all things to inquire about when reviewing the pros and cons of the various multichannel pipettes available. As we have reviewed in these two articles, there are many different pipette options ranging from single channel to many channels. By going through some basic questions, you can gain the information you need to make the best decision for your lab. Finding the best option is worth some investigation and evaluation time, as it can save you some lost production time, monetary costs, and safety related injuries down the road.
About the Author
Breeann Bryan is a dedicated laboratory professional with a LEAN Six Sigma Black Belt. Her background ranges from the bench to operations management. She is proud to share the knowledge she has gained from her experience and empower others to tackle their process improvement challenges. Whether it’s troubleshooting data quality issues or finding out how to maximize efficiency in the lab, she firmly believes that everyone deserves to have the right tools needed for the job.