Automated Sample Handling and Preparation Methods - A Complete Guide

From bloodwork analysis to drug development and vaccine research, samples form the backbone of scientific research. Automated technologies have revolutionised the way researchers handle and prepare samples in laboratories, making these key steps faster, easier and more cost effective.

Want to know more about the techniques used in state-of-the-art research centres? Below, we take a detailed look at some of the most widely used automated sample handling and preparation methods. But first, let’s define what samples are and why they matter.

Defining samples

Samples are used by researchers to develop an accurate and unbiased observation of a larger group. The sample acts as a subset of a larger set of data and should reflect the unique properties and characteristics of the overall group.

In some scenarios, one sample is enough to characterise a larger group. For example, nasal swabs collected in COVID-19 tests provide laboratory personal with a sample of the patient’s upper respiratory fluid. This small sample can then be used to detect whether the patient has been infected with the virus. Similarly, a 1ml blood sample is enough to conduct a complete blood count (CBC) and offer detailed insight into the cellular profile of a patient’s blood. Despite the small sample size, results taken from a 1ml sample represent all five litres that flow through the average adult body.

In other scenarios it may be necessary to collect multiple samples. For example, when determining whether a reservoir is suitable for oil extraction it’s best to collect multiple samples from different areas of the site. This allows for variation between samples and helps deliver a more accurate overview. When collected properly, samples are considered a reliable method of analysing a larger group and extracting meaningful data.

What is automated sample handling and preparation?

Automation has transformed a myriad of industries and the science sector is no exception. Today, modern laboratories rely on automated sample handling and preparation to increase efficiency, improve accuracy and reduce resource allocation for repetitive tasks.

Some laboratories choose to keep the sample preparation process separate from the analysis stage, while others prefer to integrate the two. The latter approach calls for specialised equipment with integrated analytical platforms. This allows samples to be loaded, prepared and analysed on the same device. There are pros and cons to both approaches, with biopharma expert Eric Grumbach commenting, “If you handle preparation separately then you’re not tying up test instrumentation while samples are being prepared.”

On the flipside, combining the preparation and analysis stages minimises user intervention and reduces the risk of contamination. An integrated approach also frees up laboratory personnel and translates to time saving benefits.

Methods vary between laboratories, with some techniques considered standard and other highly specialised. Read on to find out more about some of the different automated sample handling and preparation methods used at gold-standard laboratories.

1. Gravimetric sample preparation

Used by pharmaceutical companies around the world, gravimetric sample preparation is a reliable and cost-efficient way to improve accuracy and minimise the risk of out-of-specification (OOS) errors. The method involves weighting both the solid and the solvent, an approach that reduces sample variability and significantly lowers the risk of out-of-specification results. The four key steps of gravimetric sample preparation are summarised below:

• Set target concentration
• Weigh sample in vial and record results
• Use weight to calculate amount of solvent required
• Add solvent to sample

2. Automated Solid Phase Extraction (SPE)

When it comes to isolating trace organics from liquid matrices, no method offers better accuracy than Automated Solid Phase Extraction (SPE). Specialised systems are used to trap and concentrate analytes prior to quantification. SPE was revolutionised in 2015, when California-based laboratory instrument manufacturer Phenomenex and Swiss-based company Tecan teamed up to automate Solid Phase Extraction. The use of Strata and Strata-X SPE sorbents developed by Phenomenex, combined with advanced Freedom EVO robotic liquid handling technology from Tecan, marked a new era of efficiency for SPE. Today the highly useful method is used across a wide range of sectors, including forensics, food safety, pharmaceuticals, metabolomics and environmental science.

3. Accelerated Solvent Extraction (ASE)

Accelerated Solvent Extraction utilises high temperatures and pressures to prepare solid and semi-solid samples for analysis. Purpose-built systems are used to extract compounds using small amounts of liquid solvent. Not only does this automated sample preparation technique save time and improve accuracy, but it also reduces solvent consumption and saves laboratories money.

4. Automated Evaporation

Suitable for use with small and large sample volumes, Automated Evaporation improves laboratory productivity and accelerates the sample preparation process. The Rocket Synergy™ 2 Evaporator from Thermo Fisher Scientific sets a new standard for automated evaporation, allowing researchers to concentrate high-volume samples quickly and efficiently. The capacity to simultaneously prepare up to six 450 mL flasks for chromatographic analysis without user intervention is a huge productivity booster for time-short laboratories. Directly concentrating samples in an autosampler vial also minimises the risk of contamination to deliver more accurate and reliable results.

5. Next-Generation Sequencing

When preparing DNA for applications such as forensics, Next-Generation Sequencing (NGS) is an incredibly valuable technique. For the most accurate results scientists must have access to a well-stocked library of DNA fragments, a resource that can be difficult to build.

Thermo Fisher Scientific revolutionised the process by reprogramming its Ion Torrent sequencing system with library construction capabilities. This slashed construction time and allowed researchers to build a library in just 15 minutes.

“Library preparation is a set of fairly complex molecular bioprocesses,” explains Andy Felton, VP Product Management at Ion Torrent Systems. Depending on the processes being used, library construction requires a huge amount of manual work and can take up to seven hours. Not only is it time consuming, but Felton adds “there’s always room for error with a manual process.” As well as simplifying workflows, Ion Torrent sequencing systems make NGS easy use and eliminates the need for specialist personnel.

6. Titration

Titration is a good example of integrating the sample preparation and analysis stages. Commonly used in medical laboratories, titration uses a solution of a known concentration to determine the characteristics of an unknown concentration. For example, titration is useful when analysing the chemical content of a blood or urine sample.

While titration can be done manually, automated titration platforms significantly reduce employee workloads. In some cases, analysis is as simple as weighing a sample, placing it in the tray and pressing the “start” button. Automated titration platforms can also dilute samples, add solvents and extract liquid at the touch of a button. For high output laboratories that handle, prepare and analyse hundreds of samples a day, automated titration can be a valuable tool.

The importance of accuracy

Not only do OOS errors jeopardise results, but they can also consume a huge amount of time when investigations are launched by regulatory bodies like the US Food and Drug Administration (FDA). In the pharmaceutical industry the fines for non-compliance can be enormous. In some cases, OSS errors can have a negative impact on the reputation and profitability of a company, an upshot that was recently faced by pharmaceutical titan Johnson & Johnson. Manufacturing errors at the company’s COVID-19 vaccine production facility in Baltimore resulted in the loss of 15 million vaccines. This was not only a damaging blow to productivity and profits, but also tainted the company’s reputation.

Automated sample handling and preparation methods drastically reduce the risk of out-of-specification (OOS). Research suggests around 50% of OOS errors that appear in analytical workflows are caused by sample processing errors or human oversight. This statistic highlights the value of streamlining laboratory processes and investing in automated sample handling and preparation equipment.

The future of automated sample handling and preparation

Even over the past year, sample handling and preparation methods have advanced enormously. But according to many commentators, there’s still room for improvement. In the wake of the coronavirus pandemic, experts predict an upsurge in the capabilities of biobanks, highly secure biorepositories used to store biological samples. Mass bio-sampling will play a critical role in fast tracking the development of new treatments and vaccines. As the world recovers from the coronavirus pandemic and prepares for future outbreaks, biobanking technologies will allow researchers to easily access and analyse biological samples.

This will translate to:

• Significant time and cost savings
• Reduced risk of out-of-specification (OOS) errors
• Improved confidence in analytical results
• Reduced exposure risk for analysts
• Reduced risk of human error

A new generation of scientific instruments

Want to know more about the state-of-the-art equipment used to carry out automated sample handling and preparation? The XPR Automatic Balance, an ultra-precise weighting solution developed by US-based scientific instrument manufacturer Mettler-Toledo, is introduced in ‘How gravimetric sample preparation is helping pharmaceutical manufacturers meet the demands of consumers, regulators, and the market.’