Reliable Identification – One Tube at a Time

Secure tube identification as the basis for automated laboratory workflows.

Automated Barcode Reading of Laboratory Tubes and Vials

Reliable identification of laboratory tubes is a fundamental requirement for automated laboratory workflows. Barcode-based identification enables the unambiguous assignment of tubes to measured values, rack positions and individual processing steps throughout the workflow.

By capturing and verifying barcode information, tubes can be tracked consistently across different process stages, including weighing, filling and sorting. In addition, barcode reading allows verification of label readability to ensure compatibility with downstream systems and external laboratory infrastructure.

This level of identification forms the basis for traceability, process transparency and trust in automated laboratory operations.

How Automated Barcode Reading Works

Integrated Barcode Identification in the Multifunction Unit

All LABOTIQ Lab-Bot multifunction units are equipped with an integrated barcode reader. Standard configurations support 1D barcodes, with optional support for 2D codes depending on application requirements.

During barcode reading, the tube or vial is clamped securely between rotating rollers within the multifunction unit. The barcode reading field is positioned directly on the tube surface. While the barcode is being read, the rollers rotate the tube, guiding the barcode through the reading field. As a result, reliable barcode detection is achieved regardless of the exact barcode position on the tube.

In addition to identification, the controlled rotation of the tube allows the final orientation of the barcode to be defined precisely. This makes it possible to align barcodes consistently within racks, enabling standardized orientation for subsequent automated processes such as weighing, filling or downstream handling.

Code Types and Reading Characteristics

Depending on the application and accuracy requirements, automated weighing can be implemented in different configurations.

1D Barcodes

1D barcodes represent the most common form of machine-readable identification in laboratory environments. They are highly robust, cost-effective and well suited for automated processing. When applied correctly, 1D barcodes can be read reliably even on curved surfaces such as laboratory tubes.

For optimal readability on cylindrical tubes, the barcode lines should be oriented perpendicular to the tube’s rotational axis. Under these conditions, barcode reading remains stable and independent of the exact label position. LABOTIQ systems support common barcode standards such as Code 39, Interleaved 2 of 5, Code 128 and many others.

2D Codes

As an option, the integrated barcode reader can be replaced by a 2D code scanner. Compared to 1D barcodes, 2D codes offer increased error tolerance and allow a higher information density within a smaller area.

However, the two-dimensional structure of these codes introduces additional challenges on cylindrical surfaces. When parts of a 2D code extend around the tube’s rotational axis, optical distortion and loss of sharpness may occur, which can noticeably affect reading performance.

To ensure reliable readability, LABOTIQ recommends limiting the edge length of a 2D code to a maximum of one third of the tube diameter and using a minimum module size of 0.3 mm. Due to the wide variety of tube geometries and materials, reading tests are strongly recommended when implementing 2D codes.

Use of Barcode Reading Results

Scanned barcode data can be validated against predefined expectations as part of the automated workflow. Depending on the application, the system can verify that a tube carries no barcode at all (for example prior to labeling), that any readable barcode is present, or that the scanned code matches an expected value exactly.

By scanning the barcode after labeling, the correct execution of the labeling step itself can also be verified as part of process control. This ensures that the label content is readable and correctly applied before the tube proceeds to subsequent process steps.

If the validation criteria are not met, the tube is automatically flagged as an error and can be selectively sorted out. This ensures reliable process control, prevents mix-ups at an early stage and increases confidence in downstream automated operations.

Key Benefits

Reliable Tube Identification

Automated barcode reading enables unambiguous identification of laboratory tubes as the basis for all subsequent process steps.

Position-Independent Barcode Detection

Controlled tube rotation ensures reliable barcode reading regardless of the exact barcode position on the tube surface.

Support for Common Barcode Standards

Supports widely used 1D barcode formats such as Code 39, Interleaved 2 of 5, Code 128 and others, with optional support for 2D codes as Datamatrix and QR-Code.