Digital illustration showing temperature affecting DNA stability.

Unlocking the Secrets of Complement Biomarker Stability: How Sample Storage Impacts Your Health Data

Nico Varela in Health & Wellness November 2025 • 5 min read.

"A Deep Dive into the Effects of Temperature on C3a and C4a Levels and What It Means for Accurate Testing."

In the realm of medical diagnostics, accuracy is paramount. Every step, from sample collection to analysis, must be carefully controlled to ensure reliable results. One often-overlooked aspect is the impact of sample storage conditions on the stability of biomarkers—those telltale molecules that provide insights into our health. Recent research has shed light on the critical role that temperature plays in preserving the integrity of complement biomarkers, specifically C3a and C4a.

C3a and C4a are fragments produced during the activation of the complement system, a crucial part of the immune system that enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells, promote inflammation, and attack the pathogen's cell membrane. Changes in their levels can indicate various health conditions, making them valuable markers for diagnosis and monitoring. However, these biomarkers are susceptible to degradation if not stored properly, leading to inaccurate test results and potentially misguided clinical decisions.

This article delves into a groundbreaking study that investigated the effects of storing samples at different temperatures—specifically, -80°C versus -20°C—on the levels of C3a and C4a. By understanding the findings of this research, we can gain valuable insights into the best practices for sample storage and ensure the accuracy of complement biomarker testing, ultimately safeguarding the reliability of our health data.

Why Does Temperature Matter for Biomarker Stability?

Digital illustration showing temperature affecting DNA stability.

Temperature is a critical factor in maintaining the stability of biological molecules, including proteins and peptides like C3a and C4a. Enzymes, which are biological catalysts, can remain active even at low temperatures, albeit at a slower rate. These enzymes can degrade the biomarkers of interest, leading to inaccurate measurements.

When samples are stored at higher temperatures, such as -20°C, enzymatic activity is increased, resulting in faster degradation of C3a and C4a. In contrast, storing samples at -80°C significantly reduces enzymatic activity, preserving the integrity of the biomarkers for longer periods. This difference in enzymatic activity can have a profound impact on the accuracy of complement biomarker testing.

Enzymatic Degradation: Higher temperatures accelerate enzymatic activity, causing faster degradation of C3a and C4a.
Preservation at -80°C: Storing samples at -80°C minimizes enzymatic activity, maintaining biomarker integrity.
Inaccurate Measurements: Improper storage can lead to skewed test results due to biomarker degradation.

To illustrate the impact of temperature on biomarker stability, let's consider the findings of the study mentioned earlier. Researchers collected EDTA plasma from healthy donors and divided each sample into multiple aliquots. Ten aliquots were stored at -20°C, while two aliquots were stored at -80°C as controls. The levels of C3a and C4a were then measured in all aliquots using radioimmunoassay (RIA) over a period of four weeks.

The Bottom Line: Prioritize Proper Sample Storage for Reliable Results

In conclusion, the stability of complement biomarkers, particularly C3a and C4a, is significantly affected by sample storage temperature. Storing samples at -20°C can lead to biomarker degradation and inaccurate test results, while storing samples at -80°C helps to preserve their integrity. These findings highlight the importance of prioritizing proper sample storage practices in clinical laboratories and research settings. By adhering to recommended guidelines, we can ensure the accuracy of complement biomarker testing and improve the reliability of our health data, leading to better-informed clinical decisions and improved patient outcomes.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

Everything You Need To Know

What are C3a and C4a, and why are they important in medical diagnostics?

C3a and C4a are fragments produced during the activation of the complement system, which is a crucial part of the immune system. They help antibodies and phagocytic cells clear microbes and damaged cells, promote inflammation, and attack pathogens. These biomarkers are valuable for diagnosing and monitoring various health conditions because changes in their levels can indicate immune system activity and potential health issues. Their accurate measurement is vital for making correct clinical decisions.

How does temperature impact the stability of C3a and C4a in stored samples?

Temperature significantly affects the stability of C3a and C4a because of its influence on enzymatic activity. Higher temperatures, such as -20°C, increase enzymatic activity, which causes faster degradation of C3a and C4a. In contrast, storing samples at -80°C minimizes enzymatic activity, preserving the integrity of these biomarkers for longer periods. This means that the storage temperature directly affects the reliability of the test results. Inaccurate results may lead to incorrect diagnoses.

What are the main differences between storing samples at -20°C versus -80°C, regarding C3a and C4a stability?

The primary difference lies in the rate of enzymatic degradation. Storing samples at -20°C allows for increased enzymatic activity, which leads to the degradation of C3a and C4a over time. This can result in inaccurate measurements and unreliable results. Conversely, storing samples at -80°C significantly reduces enzymatic activity, preserving the integrity of C3a and C4a. This ensures that the measured levels accurately reflect the patient's condition at the time of sample collection. Using -80°C is considered the best practice.

Why is proper sample storage crucial for accurate complement biomarker testing, and what are the consequences of improper storage?

Proper sample storage is crucial because the accuracy of complement biomarker testing directly depends on the stability of C3a and C4a. If samples are not stored correctly, these biomarkers can degrade, leading to inaccurate test results. The consequences of improper storage can include misdiagnosis, inappropriate treatment, and compromised patient outcomes. Incorrectly measured levels of C3a and C4a can mislead clinicians, affecting their ability to make informed decisions based on these biomarkers. Therefore, following recommended storage guidelines is critical to ensure reliable and trustworthy health data.

In the context of the study, what methods were used, and what were the key findings regarding C3a and C4a levels?

The study involved collecting EDTA plasma samples from healthy donors. These samples were divided into multiple aliquots. Ten aliquots were stored at -20°C, while two were stored at -80°C as controls. The levels of C3a and C4a were measured in all aliquots using radioimmunoassay (RIA) over four weeks. The key findings were that storing samples at -20°C led to the degradation of C3a and C4a, resulting in inaccurate test results. In contrast, storing samples at -80°C helped preserve the integrity of these biomarkers, providing more accurate and reliable measurements. This highlights the importance of temperature for biomarker stability.