Blood Specimen Collection Systems Explained: Regulatory Pathways, Specimen Stability and Test Performance

After my most recent post, I received many questions about the different types of blood‑derived specimen collection, preservation, and transport systems. One theme stood out: confusion about how these systems differ and what those differences mean from a regulatory and test performance standpoint.

Innovation Is Transforming Blood Collection

Over the past decade, specimen collection technologies have evolved rapidly. Many of these innovations are patient‑centered by design, aiming to make the process more convenient, less intimidating, and in some cases more accessible. But with innovation comes complexity especially when it comes to regulatory classification and diagnostic test validation requirements.

Traditional Specimen Collection

These systems rely on venipuncture performed by a trained healthcare professional and support collection of whole blood, plasma, and/or serum. Any required pre‑shipment processing (centrifugation, aliquoting, etc.) must also be performed by the healthcare professional.

Shipping conditions, such as dry ice, cold packs, or ambient, depend on analyte stability.This approach has been the workhorse of clinical laboratory diagnostics for decades and remains the gold standard for many diagnostic assays.

Dried Blood

Dried blood collection and transport methods use finger‑stick capillary blood applied to a solid matrix, which is dried before shipping.

Key advantages include:

• Flexibility in where and when the specimen is collected

• Simplified shipping logistics

• A less anxiety‑inducing alternative for patients who fear venipuncture

However, dried blood is not universally compatible with all analytes or test methodologies. Laboratories must confirm that the target analyte can be reliably measured from dried matrix. Sometimes the test performance characteristics do not match those observed for venipuncture, unfortunately.

Novel Blood Collection Devices

This category has seen the most dramatic innovation in recent years, enabling high‑sensitivity testing for certain diseases using small‑volume or stabilized specimens.

Because of their design and intended use, many of these devices are classified as Class II medical devices by the FDA, which carries specific regulatory obligations for manufacturers and laboratories.

Collection Tubes with Preservatives

These tubes still require venipuncture, but they introduce chemical preservatives at the point of collection to stabilize specific analytes.

Key implications:

• The chemical modification of the specimen typically results in Class II medical device classification

• Laboratories must characterize assay performance characteristics, including analyte stability, recovery, and any matrix effects introduced by the preservative

Alternate‑Site Capillary Collection Devices

Generally, these devices attach to the upper arm (or another site) using suction, deploy an internal lancet, and collect blood into an attached tube.

Considerations include:

• Potentially reduced patient anxiety due to alternate collection sites

• The need for laboratories to verify that sufficient analyte is present in the collected specimen

• Validation of analyte stability during shipping

The Bottom Line

The past decade has seen innovation in the area of blood‑derived specimen collection, preservation, and transport. These advancements can improve the patient experience, expand access, and enable new types of testing, and they may introduce regulatory considerations and assay validation requirements.

If your laboratory is considering implementing a new specimen collection, preservation, or transport system, you should consult an expert to ensure:

• Your test maintains acceptable performance

• Your validation strategy is appropriate

• Your regulatory pathway is correct and defensible

A thoughtful approach now prevents costly missteps later (Contact Us).