Weighing samples is one of the most common activities in biopharmaceutical laboratories. Accurate sample weights are critical for activities ranging from material characterization in early R&D (e.g., density determination and purity analysis) to material and conformance testing in late-stage development and manufacturing.
Yet, digitizing a sample weighing workflow with an intuitive user experience remains challenging. Lab analysts often resort to outdated workflows where they manually capture and record the results of their measurements.
This introduces inefficiencies, high error rates, and risks to data integrity. Documenting weighing activity demands analysts to capture various metadata—such as sample ID, batch number, balance name, and serial number—to adhere to ALCOA++ principles. Manual collection of this metadata is prone to errors, and even implementing the four-eyes principle cannot entirely eliminate the potential for oversight.
Therefore, automatically capturing weight outputs of balances can significantly improve efficiency, accuracy, and compliance. However, lab organizations often struggle to find the best approach to do so.
Why is digitizing the weighing process challenging?
- Data interface of balances: Most balances have only a serial port as the data interface, without standardized means of entering sample information or other key metadata. As a result, the measurement data lacks the necessary context.
- Laboratory constraints: Automated capture of sample weights typically requires a nearby PC to allow analysts to perform the weighing operation and interact with a software interface at the same time. However, limited space, network availability, or a lack of widely deployed PCs in labs can hinder this setup.
- Diversity of vendors/models: A typical enterprise biopharmaceutical company can easily have several hundreds of balances from tens of different vendors and model series, complicating the development of a universal solution for all vendors and models.
- Cost considerations: Current solutions to digitizing the documentation of weighing workflows (see next section) can seem cost-prohibitive, especially since balances are less expensive than other instruments like HPLC systems and costs can seem disproportionate.
Current approaches and considerations
There are two main approaches currently used in the industry:
While both approaches have merits, they can be impractical for enterprise biopharmaceutical companies with a diverse vendor ecosystem for balances and multiple ELN/LIMS platforms.
The new TetraScience approach: a lightweight, dedicated data capture app for the lab
Instead of an instrument- or ELN/LIMS-centric approach, we take a data-centric and fundamentally vendor-agnostic approach that uses a dedicated data capture app with a lightweight user interface.
Our solution meets the following requirements:
- Compatible with all makes and models of balances
- Compatible with all ELN/LIMS
- Easily deployable in the lab, such as on a tablet or existing lab computer
With our app, the scientist’s experience is significantly improved:
- The user creates or is assigned a single or a list of weighing tasks in the LIMS or ELN.
- The LIMS or ELN sends the list of samples to TetraScience, which are then displayed in the Tetra Data Capture App for each assigned user.
- Analysts weigh the samples and use the app to capture balance readings through OCR (optical character recognition).
- The readings are associated with sample information, and thus contextualized. The data is transferred to the LIMS or ELN, where users can access it.
Comparison of approaches
GxP compliance
Having a dedicated user interface for data capture is well-suited for regulated environments, incorporating key compliance features:
- Simultaneous device identification and data reading: The balance can feature a QR code containing its ID, which is captured alongside the balance reading in a single image, ensuring clear and traceable data lineage.
- Inclusion of metadata: All readings are automatically tagged with precise date and time stamps.
- Operator identification: The app requires a unique user login, ensuring operator identification for each measurement.
- Prevention of image reuse: The app does not allow an image to be used for more than one reading.
- Audit trail: The app maintains a complete audit trail of the weighing activity.
Bring tablets to your lab
Using tablets in the lab offers great advantages due to their small footprint. Furthermore, tablets provide a future-proof platform to introduce other capabilities and user interactions.
Here are some recommendations for rolling out tablets in your lab:
- Approval, security, and installation of devices: Personal devices are not recommended for lab use; instead, labs should use dedicated tablets, similar to scientific equipment that is assigned to a specific lab.
- Contamination of the device and cross-contamination of substances: Contamination can be avoided by using a sterile plastic cover on the tablet, similar to how balances with a touch screen are protected.
- Upgrade and maintenance of devices and the app: Tablets can be managed and maintained using existing mobile device management (MDM) tools.
Beyond balances and OCR
Thus far, our focus has been on weight measurements for data capture, but the same approach can be applied to other "simple instruments" like pH meters and workflows such as pH calibration.
More broadly, many instruments lack advanced capabilities such as control software, file export options, or programmatic interfaces. Examples include osmometers, melting point apparatuses, dissolution testers, hardness testers, blood gas analyzers, and biospectrometers.
Currently, extracting data from these instruments often involves printing the results on paper and either transcribing them into other systems or taking a photograph of the printout. While these instruments are not inherently "simple," the rudimentary nature of their data output and metadata integration has led biopharma companies to categorize them as “simple instruments.”
The Tetra Data Capture App can be adapted to support these "simple instruments" by tailoring the data capture logic. Future iterations of the app aim to address the diverse interfaces of such devices, enhancing data acquisition capabilities beyond OCR. We envision the app enabling communication via serial-to-ethernet or serial-to-Bluetooth connections, supporting various data exchange protocols, and parsing data from "simple instruments" into structured formats.
With the Data Capture App handling data acquisition, the role of the ELN or LIMS platforms is streamlined: they simply send a list of samples to be measured and await the results. This approach enables faster deployments.
Conclusion
In this article, we explored three approaches to digitizing the documentation of weighing workflows: two existing methods and the new TetraScience approach.
- Mettler Toledo LabX: This solution is ideal for organizations that standardizes all balances to Mettler Toledo and do not require a generalized approach for integrating other “simple instruments.”
- ELN/LIMS integration: This approach suits biopharma organizations willing to invest in extensive customization and tightly couple their informatics systems with lab equipment.
- Tetra Data Capture App: If your organization manages a diverse instrument landscape and multiple ELN/LIMS platforms, or seeks to avoid overloading your ELN/LIMS with added complexity, the Tetra Data Capture App provides a scalable, vendor-agnostic, and cost-effective alternative.
Curious to see the Tetra Data Capture App in action? Watch our video.