Automating Normalisation

Normalisation is a fundamental step in many laboratory workflows, particularly in molecular biology, genomics, and drug discovery. It involves adjusting the concentration of a sample — such as DNA, RNA, proteins, or small molecules — to a specific, uniform level across a set of samples. This ensures consistency, accuracy, and reproducibility in downstream processes like PCR, next-generation sequencing (NGS), or high-throughput screening.

For instance, in a genomics workflow, DNA samples from different sources may have varying concentrations. If these variations are not  corrected, they can lead to inconsistent amplification, biased sequencing results, or unreliable data interpretation. Normalisation ensures  every sample starts from an equal baseline, enabling fair comparisons and robust results.

While normalisation is a fundamental step in many workflows, performing it manually is far from straightforward. It involves a series of  calculations and precise liquid handling that can quickly become tedious and error-prone, especially when dealing with large sample sets.  

Here’s why manual normalisation can be such a bottleneck:

Normalisation requires calculating the volume of diluent and stock solution needed to achieve the desired concentration for each sample.  This process can be manageable for a small number of samples, but as the sample set grows, so does the risk of calculation errors.  Missteps in these calculations can lead to inconsistent sample concentrations, which jeopardise downstream results

Pipetting the calculated volumes accurately and mixing consistently is critical, especially for low-volume adjustments. Variations in pipetting  technique, fatigue, or using improperly calibrated pipettes can introduce inconsistencies. Even slight deviations can result in significant differences in concentration, compromising the entire dataset.

For labs handling dozens or hundreds of samples, normalisation can take hours to perform manually with a single channel pipette. Each sample requires individual calculations, pipetting, and careful tracking leaving the time saving manual multi-channel pipettes on the shelf.  The repetitive nature of single channel manual pipetting also increases the likelihood of mistakes such as skipping samples or mislabeling tubes.

Frequent handling of samples during manual normalisation increases the risk of cross-contamination. This is particularly problematic in  workflows involving sensitive downstream applications, where even minor contamination can yield unreliable results.

Tracking and documenting manual normalisation steps can be cumbersome. It’s easy to overlook details, misrecord values, or lose track of  progress during long workflows. These issues make it difficult to trace errors if problems arise later in the process.

Manual normalisation, while feasible, is a process fraught with inefficiencies and potential for error. These challenges can significantly impact the quality, reproducibility, and throughput of your work—making a strong case for automation.

Here’s how automation using i.prep stacks up against the challenges of manual normalisation.

<flow>'s integrated normalisation operation can instantly calculate the required volumes of stock solution and diluent for each sample based on their initial concentrations and desired final concentrations. These automated calculations eliminate human error, ensuring consistent and accurate adjustments across all samples. A CSV file with the initial concentrations can be imported speeding up this process.

i.prep is designed for precision. This removes the variability caused by differences in manual pipetting techniques, ensuring uniform sample  concentrations that meet the most stringent requirements for reproducibility.

What might take hours manually, reseting the volume and keeping track of transfers, can be completed in a fraction of the time. i.prep can simultaneously process multiple samples, pipetting and mixing as required, with independent multi-channel control. This frees up your time  to focus on higher-value tasks.

i.prep reduces human contact with samples, significantly lowering the risk of cross-contamination. The compact form factor of i.prep allows it to be placed within a medical cabinet, or fume hood, and wirelessly controlled using the <flow> software.

The software records every step of the process, including sample volumes, concentrations, and any adjustments made in its  workflow run log. This creates a comprehensive audit trail, making it easy to trace errors, ensure compliance with lab standards, and maintain reproducibility across experiments.

For labs processing hundreds or even thousands of samples, i.prep is indispensable. i.prep is the perfect companion to larger liquid handling systems freeing them up to perform higher-throughput applications. The open API can also be utilised to integrate i.prep into third party scheduling and control systems.

Automating the normalisation process not only improves the quality of your data but also enhances the productivity of your lab, allowing you  to focus on groundbreaking discoveries instead of boring, repetitive tasks.