Automated Liquid-Handling Systems And The Basis Of Their Modality

Laboratory automation has been a part of life sciences for a long time. For a long time, large-scale pharmaceutical companies have been using liquid-handling robots for high-throughput developments and drug discovery. Robots have made it possible to screen countless compounds in short periods of time and are able to identify a single candidate drug. Robots can also dispense tiny amounts of volumes precisely of fragile bioactive samples negating the possibility of contamination. There are certain considerations for these automatic liquid-handling systems, which will be discussed here. 

Pipetting Channels

There can be a considerable variation of pipetting setup among liquid handling workstations. Laboratories meaning to transition to automation processes need to carefully consider the number of channels and the pipetting ranges that suit their needs. Liquid-handling workstations are usually capable of accommodating a specific arrangement of both pipetting arms. For instance, two single or even multi-channel pipetting arms of a specified volume range at a particular time. They are usually interchangeable for pipettes of different other volumes. There are some sophisticated models like Hamilton Microlab NIMBUS96, which has up to eight independent channels with a dynamic pipetting range between 0.5ul to 1000ul. 

Control Centers

Control centers coordinate the robot operations that take place in a workstation. Whether the robot has fixed operations or can accommodate new protocols, it is fundamental to consider the usability of a system. Engineers and programmers are relatively scarce in life science laboratories, therefore, the sustainability of automated liquid-handling systems relies on their daily use and how user-friendly they are. Most systems can be managed by the software installed on an externally attached tablet, which is operated by touch screens. Less sophisticated and traditional models might still have the need for a connected computer, which makes the whole set-up even bulkier. In such cases where the operations of the workstation can be customized by the users depending on evolving protocol requirements, the process to program the workflow also has to be uncomplicated and simple. The majority of newer models propose control centers where the workflow can be modified or designed using drag-and-drop icon-based tasks.

Decontamination & Washing

The risk of contamination is one of the biggest issues in genomics labs. Liquid-handling robots come with washing modules that perform cleaning of robot heads after usage. There can also be the option of incorporating a microplate washer for well plates. The washing module comprises pumps that pass water and detergents through the robot head and the aspiration of waste. The workstations that do not have washing systems are commended for running washing solutions through pipettes as a way of cleaning. Another option is to use pipetting robots, which make use of automation Tips for Hamilton and labware, which reduce the requirement of cleaning. However, there are certain experiments, which involve microbial samples that can also require decontamination. In these cases, higher-end workstations are preferable as they include an integrated UV light module. In cases of acoustic droplet ejection systems like the Echo 650 series, the dispensing of liquid does not involve any contact, which eliminates the sources of contamination. 

Accuracy & Precision

Life sciences and particularly genomics require high degrees of precision and accuracy in pipetting volumes to guarantee the success rate and reliability of experiments. Precision means the consistency of the pipetting experiments, whereas accuracy stands for the actual amount of volume handled. If there are pipetting errors, then there are chances of misleading measurements of DNA concentrations. It can also become even trickier when genomics protocols need tiny volumes of extremely precious samples and reagents that cannot allow even a negligible chance of error. Therefore, liquid-handling workstations are usually fitted with several technologies to obtain the precise amount of pipetting.

Labware Features To Look For

If you are looking to stock up on liquid handling devices, here is a list of things to consider:

1. Channel number
2. Compatibility with labware
3. Performance and precision
4. Accuracy
5. Size
6. Volume range
7. Throughput capability

Factor To Be Considered

There are also a number of factors to consider while selecting your liquid handling gear. Cost, automation, and ergonomics are some significant elements. Identify your lab requirements by asking yourself these questions:

1. Is there enough space in the lab for the proposed system installation? Ask the manufacturer if the same equipment can be delivered in a more compact size in case the space requirements are not met.
2. Is there potential for upgradation in case the system expands in size?
3. What level of speed, volume, accuracy, and precision does the equipment offer?
4. What is the number of plates that require weekly processing?
5. If you are opting for an automated system, you must know how easy-to-use and versatile the software of the system is.
6. What ergonomic features does the manual handling device provide?

Types Of Liquid Handling Devices

There are various types of liquid handling devices, each designed for specific applications and sample storage. However, the most commonly used labware for liquids include:

• Manual Pipettes

Pipettes are designed to measure and dispense small amounts of liquid volumes. It is a handheld device that offers numerous applications in biotechnology, sciences, and pharmaceutical fields. They come in different types and volumes. You can manual pipettes in different types and capacities, including aspirating pipettes and serological pipettes in 10 ml, 50 ml, and 100 ml capacities.

• Electronic Pipettes

The motor component of an electronic pipette helps avoid barrel contamination and the formation of air bubbles in liquids. By regulating the dispensing rate and amount of aspiration, this device prevents measurement errors that are common in liquid studies. Electronic pipettes are programmable, requiring repetitive pipetting for optimal results.

• Bottle Top Dispensers

As the name suggests, the bottle top dispenser allows dispensing of specified quantities of liquids. 1 to 100 ml of chemicals, oils, and solvents present in similar containers can be dispensed with the help of this tool. It helps prevent reagent loss and delivers higher efficiency for accurate results.

• Pipette Tips

Pipette tips come in a cone shape, and they are attached to the top of a pipette. They are available in disposable, sterile, and autoclavable varieties, so you never have to use a contaminated pipette tip for any experiment. You can get them in non-sterile, pre-sterilized, or filtered formats for different applications.

• Pipette Fillers

Pipette fillers work on the mechanism of pressure and suction. They are one of the most important lab instruments, used to drain liquids from pipettes. The process is performed in a highly controlled environment as the filling and draining of liquids from a pipette can result in spills, contamination, or evaporation.

• Burettes

Burettes are specifically designed for titration experiments in which small amounts of volume is dispensed drop by drop. It is a glass tube with a tap used to deliver liquid into a solution in the form of drops. The tap is located at the end of the long tube, which comes in both digital and manual formats.

Here is the ultimate guide for lab technicians trying to choose a liquid handling device for their experiments. Whether you need individually wrapped serological pipettes or automation filter tips, you can get them from Molecular Biology Products. Visit our website to get access to all types of liquid handling products.

Verification Method of Pipettes on Automated Liquid Handlers

Working in laborites is difficult and complex. It looks like a private and maintained workspace, but a lot goes on in there. There are chemicals, materials, and equipment to be handled. All of this requires great care as the results of anything that goes in the lab should have precision.

Advancements in equipment and apparatus keep happening for the sake of precision. The advancements also help in the ease of handling the material and apparatus. With each passing day, modern automated machinery has been taking over. This is because machines tend to avoid errors at a greater level than we humans.

However, these machines do have to go through testing before they serve an official purpose. The equipment, such as automation tips for Tecan, used with automated liquid handlers (ALHs), is tested regularly. Anyone working with them can test these quickly. Here you will learn how. The simple, easy, and fast test method will verify the performance of the pipette mounted on ALHs as required for laboratories working under ISO 17025.

Introduction of Test

Automated Liquid Handlers (ALHs) help in improving the accuracy required while pipetting. They also help in decreasing the intensive labor required for manual pipetting. Many methods are already done to verify the performance of ALHs, such as photometric, fluorescence, and gravimetric being the main ones.

Any laboratory working under ISO 17025 performing their calibration should have a method that they apply to test the certainty and uncertainty of those calibrations. Even the vendors of ALHs have their methods to calibrate and test the equipment. The problem with vendors’ methods is that they are not well documented, are expensive, and have to be installed on each instrument.

The method you are going to read below is fast, easy, and inexpensive. Do note that you can only apply it to volumes between 1 and 200μL. You will also need a spectrophotometer for the reading of microtiter plates.

Experiment

• A stock solution of 10 mg/mL of OrangeG (O7252, Sigma) in MilliQ water was prepared. Photo-induced decomposition was avoided
• The stock solution was stirred vigorously for 24 hours on a magnetic stirrer
• Two solutions were taken out of this stock solution; A was 1:7.5 dilution, and B was 1:75 dilution. ‘A’ was used for volume below or equal to 10μL. ‘B’ was used for volumes above 10μL
• The solutions A and B were then processed as per Table 1. After this, the 96-well flat-bottomed microtiter plates were used to distribute the standard rows as per the figure below.

After this, various volumes are tested on ALHs. Any volume below and equal to 10μL were tested with the same method, while there was a different method for volumes above 10μL.

Measurements of Absorbance

The plates were removed from ALHs once OrangeG was added. They were covered with a seal. The plates were incubated in a shaker at 150 RPM. Incubation was carried out for 1 hour then absorbance was measured. Readings were taken with the help of a Sirio S spectrophotometer at 450 nm with the software named BrioWin Ver.

Analysis

The average of the readings from standards was taken. As per the average, a curve was calculated through linear regression and Excel.

Plates with a standard curve with R2 reading greater than 0.99 were taken for further processing. The rest were inspected and then repeated. Through the same standard curve, a volume that was dispensed by each pipette on ALHs was calculated. It came from the average values of replicates in columns from one to eight.

Conclusion

Automated liquid-handling systems carry the potential to optimize the genome sequencing outputs significantly in terms of both time and cost. As the requirement of biological labs becomes more and more clear, the properties of pipetting robots are also beginning to evolve, which lay emphasis on the specificity of automated liquid-handling needs.