A Validation Plan to Avoid Distorting Swab Test Results – Daily Business

Changing the tube used for swab collection or transport may seem like a technical change concerning only the consumable itself. In IVD diagnostics, however, its impact must be assessed in relation to the entire analytical process. The tube material, cap, coating, stabilizing additives, or sterilization method may all affect the sample and the result obtained. That is why, before implementing a new product, a validation plan is needed to demonstrate that the change does not worsen the test parameters.

Why changing tubes in IVD diagnostics requires validation

The tube is a component that comes into direct contact with biological material. If its material, design, component supplier, or the composition of the stabilizer used changes, it must be assessed whether the modification could affect the safety, performance, or declared parameters of the IVD test. The scope of such an assessment should result from the risk analysis and the nature of the specific application.

It is worth including the specifications of both the current and the new product in the change plan. The following should be compared, among other things:

• tube and cap material,
• capacity,
• presence of coatings and additives,
• packaging method,
• storage requirements.

This makes it possible to determine which properties may be relevant to swab collection, transport, preparation, and analysis.

Potential risks to the reliability of swab results

One of the primary risks when changing tubes is analyte degradation. Inadequate stabilization may affect the preservation of RNA, DNA, or proteins, and a change in the surface properties of the tube may increase adsorption of material to its walls or cap. As a result, a different amount of the target component may reach the next stage of analysis than with the previously used solution.

The change may also negatively affect sample purity. Process residues, endotoxins, or substances that may act as inhibitors can interfere with reactions used in molecular diagnostics.

Key elements of an IVD tube validation plan

The validation plan should define:

• the scope of the change,
• the methodology used,
• resources,
• timeline,
• acceptance criteria,
• the method for documenting results.

An important element is also the risk assessment indicating which features of the new tube require detailed verification.

In practice, several areas should be taken into account:

• product specification – material, design, volume, cap, coatings, and additives,
• compatibility with the IVD system – the effect of the tube on sample transfer and the analytical process,
• analyte stability – sample preservation over a defined period, during transport and storage,
• comparison with the current solution – analysis of results obtained using both variants,
• batch-to-batch variability – verification that subsequent batches maintain the required properties,
• packaging integrity – assessment of tightness and resistance to transport and storage conditions.

Tests performed with the actual IVD system are of particular importance. They should make it possible to assess the impact of the change on parameters such as sensitivity, specificity, precision, and measurement accuracy, depending on the nature of the specific test.

Sterility testing and compliance with IVD certification

If the large plastic tubes being implemented are declared sterile, the sterilization process and its impact on the product must be verified. Depending on the technology used, the following are analyzed, among other things:

• process parameters,
• biological indicators,
• sterilization residues,
• any changes in material properties.

For a product declared sterile, it is important to confirm that the required sterility assurance level has been achieved, including SAL 10⁻⁶, if that level is appropriate for the intended application.

How to implement new tubes without distorting test results

The introduction of a new tube variant is best managed as a controlled change. First, the risk should be determined, and then the studies needed to demonstrate equivalence or an acceptable impact of the new component on the process should be defined.

A good approach is to test control samples and appropriately selected patient samples in parallel using both the old and the new solution. The results should be analyzed for differences, value shifts, and variability. It is also worth separately checking analyte stability under conditions corresponding to actual transport and storage.

Before implementation, the cleanliness of the tubes, the presence of potential inhibitors, and the results of negative controls must also be verified. After validation is completed, the documentation, instructions for use, and laboratory procedures should be updated, and personnel should be informed of the change. For subsequent deliveries, it is advisable to carry out batch control in order to detect deviations that could affect results.

When implementing new tubes, it is worth using supplier documentation confirming product parameters, declared compliance, and quality control results. The Noex Labware offering includes solutions intended for laboratory and diagnostic applications, together with documentation that facilitates assessment of their suitability for the IVD process.

The most important stages of implementing new tubes in the laboratory

• A change in the material, design, or supplier of tubes may affect sample properties and requires risk assessment.
• Validation should include, among other things, analyte stability, cleanliness, compatibility with the IVD system, and comparison with the current component.
• For sterile tubes, the sterilization process, its impact on the material, and the relevant documentation must also be additionally verified.
• The new solution should be implemented as a controlled change, with defined acceptance criteria and subsequent control of future batches.

FAQ

Can changing IVD tubes affect swab test results?

Yes, changing tubes without appropriate validation may lead to distorted swab test results. It is crucial to ensure that the new product complies with IVD requirements.

What tests should be carried out when implementing new tubes?

Sterility tests, sample stability tests, and material compatibility tests in relation to IVD requirements should be performed. It is also important to check the effect of the tube on the sensitivity and specificity of the test.

Does every change of tube manufacturer require a new validation plan?

Yes, every change of tube manufacturer or model should be preceded by a new validation plan to ensure the safety and reliability of results. The scope of testing should result from the risk assessment of the specific change.

How can tube compliance with IVD certification be ensured?

It is recommended to choose tubes with appropriate IVD certificates and documentation confirming their compliance with legal requirements and quality standards. Before implementation, it should also be assessed whether the component change requires additional evaluation or documentation updates.