10 Things That Can Go Wrong Before a Blood Sample Reaches the Lab
Every blood sample tells a story, but that story can change long before any laboratory instrument begins an analysis. The period between specimen collection and laboratory processing—known as the pre-analytical phase—is responsible for the majority of laboratory errors. Pre-analytical errors are estimated to account for up to 70% of all mistakes made in laboratory diagnostics (EJIFCC).
For clinical research, these errors are more than inconveniences. They can compromise biomarker integrity, introduce variability, delay studies, and increase costs by requiring repeat collections or excluding valuable samples. Understanding the most common pre-analytical risks helps researchers design studies that generate more reliable, reproducible results.
1. Incorrect Patient Identification
Every specimen must be linked to the correct participant. Even a simple labeling mistake can invalidate an entire dataset, particularly in longitudinal studies where samples are collected over multiple visits.
Standardized labeling procedures, barcode systems, and participant verification protocols help reduce identification errors before specimens leave the collection site.
2. Choosing the Wrong Collection Tube
Different laboratory assays require different collection tubes, anticoagulants, and preservatives. Using the wrong tube may interfere with downstream analyses or alter biomarker stability.
For example, plasma, serum, DNA, RNA, and cellular assays each have unique collection requirements. Selecting the appropriate tube before collection prevents unnecessary sample loss and repeat collections.
3. Improper Blood Draw Technique
Collection technique directly affects specimen quality. Difficult venipunctures, prolonged tourniquet application, excessive aspiration, or drawing blood through improperly placed intravenous lines can all influence laboratory results.
Poor technique also increases the likelihood of hemolysis, one of the most common reasons blood specimens are rejected before testing.
4. Hemolysis
When red blood cells rupture, intracellular components are released into the surrounding plasma or serum. This process, known as hemolysis, can significantly alter concentrations of potassium, enzymes, proteins, and numerous biomarkers.
Hemolyzed specimens may no longer accurately represent a participant’s biological condition, making them unsuitable for many research applications (Clinical Chemistry and Laboratory Medicine).
5. Delayed Processing
Blood remains biologically active after collection. Cells continue consuming nutrients, releasing metabolites, and altering the composition of surrounding plasma if specimens are not processed within validated timeframes.
These changes can affect sensitive biomarkers, including cytokines, circulating nucleic acids, metabolites, and proteins (iScience). Prompt centrifugation and aliquoting help preserve specimen integrity for downstream assays.
6. Temperature Excursions During Transport
Temperature control does not end once a sample leaves the collection site. Exposure to excessive heat or freezing conditions during transportation can degrade analytes before the specimen reaches the laboratory.
Validated shipping containers, continuous temperature monitoring, and clearly defined transport protocols help maintain specimen stability throughout transit.
7. Incomplete Mixing of Collection Tubes
Many blood collection tubes contain anticoagulants or preservatives that require gentle inversion immediately after collection. Failure to mix tubes properly can lead to clot formation or uneven distribution of additives.
Even small inconsistencies during this step may influence downstream molecular and cellular analyses.
8. Improper Centrifugation
Centrifugation separates plasma or serum from cellular components, but speed, temperature, brake settings, and timing all influence separation quality.
Improper centrifugation may leave residual cells in plasma, allowing continued cellular metabolism that alters biomarker concentrations long after collection.
9. Documentation Errors
Accurate documentation is just as important as specimen quality. Missing collection times, incomplete processing records, incorrect storage temperatures, or gaps in chain-of-custody documentation can reduce confidence in study data.
Well-designed laboratory information management systems (LIMS) and standardized workflows help ensure every specimen remains fully traceable throughout its lifecycle.
10. Inconsistent Standard Operating Procedures
Multicenter studies often involve numerous collection sites, each with different personnel and workflows. Without standardized operating procedures, seemingly minor differences in collection or processing can introduce significant variability across the study.
Consistent protocols, personnel training, competency assessments, and quality monitoring help ensure every participant’s specimen is handled the same way regardless of where it was collected.
Small Errors Can Have Large Scientific Consequences
Most pre-analytical errors are preventable, yet even small deviations can influence study outcomes. A processing delay of only a few hours, an improperly mixed collection tube, or a temporary temperature excursion may alter biomarker measurements enough to affect statistical analyses or reduce reproducibility.
Because these variables occur before laboratory testing begins, they often remain invisible when investigators review final datasets. Recognizing and controlling these risks is essential for producing high-quality research-grade biospecimens.
Building Quality into Every Step
High-quality laboratory data begin long before a specimen reaches an analyzer. Standardized collection procedures, validated logistics, controlled processing environments, and rigorous quality systems work together to preserve the biological information contained within every sample.
At Avrok Biosciences, we manage every stage of the specimen journey in one facility—from collection and logistics to laboratory processing, specialty testing, and long-term biobanking. By controlling the variables that matter most before analysis begins, researchers can move forward with greater confidence in the quality and reliability of their study data. This integrated approach reduces handoffs between vendors, minimizes opportunities for error, and ensures that every step is performed under consistent, validated conditions. Our teams follow harmonized protocols supported by real-time tracking, environmental monitoring, and comprehensive documentation, allowing full transparency into how each specimen is handled. As a result, researchers gain not only high-quality samples, but also the assurance that their data are built on a foundation of controlled, reproducible processes that support regulatory expectations and scientific rigor.