The Scoop - No.1, January 2025
A Greiner Bio-One Newsletter
GEL SEPARATORS - HOW DO THEY WORK?
Gel Separators are used to separate serum or plasma from blood cells. Using tubes with gel separators enhances efficiency and improves sample quality. Greiner Bio One’s gel separator consists of a polymer that settles based on specific gravity. The gel is a thixotropic substance, meaning its viscosity changes under stress. When centrifuged, the gel temporarily liquifies, allowing density and gravity to guide it up the tube wall. It then forms a stable barrier between the serum or plasma and the red blood cells below. When the centrifuge stops spinning, the gel’s viscosity will return to its initial semi-solid state.
Image Description:
Serum sample after being centrifuged straight after blood collection. The fibrin thrombus in the serum can be seen.
KEY POINTS:
- The gel does not mix with the specimen.
- Serum gel separator tubes must clot for a minimum of 30 minutes. [See photo above].
- Horizontal swing-out rotor centrifuges provide better gel stability than fixed angle rotors.
- Centrifugation speed and temperature must comply with your region’s IFU.
- Excessive centrifugation time or speed can cause hemolysis.
- Tubes should be kept upright following centrifugation. This practice minimizes the possibility of
- specimen leakage and allows specimens to avoid prolonged contact with the tube stoppers. [1]
SOURCES
1. CLSI PRE04-ED1:2023 Handling, Transport, Processing, and Storage of Blood Specimens for Routine Laboratory Examinations, 1st Edition.
REDUCING NEEDLESTICK INJURIES AT SHANNON MEDICAL CENTER
Kelli Hill, Director of Infection Control and Employee Health and Safety at Shannon Medical Center (SMC), is a registered nurse and certified in Infection Prevention and Control. Safety is central to SMC’s mission to deliver exceptional care.
In 2019, Kelli noticed a concerning trend in wing set needlestick injuries. Collaborating with nursing and lab leadership, she led an initiative to enhance both processes and products for wing set collection. After evaluating several options, SMC selected the VACUETTE® EVOPROTECT, implementing it in December 2022. This implementation reduced needlestick injuries by 85%. In the fall 2023, Shannon Medical Center earned an “A” Hospital Safety Grade from The Leapfrog Group, a national nonprofit promoting patient safety in hospitals and surgery centers.
We proudly celebrate SMC’s achievements and remain dedicated to supporting their commitment to safety and exceptional patient care.
MEET OUR GLOBAL DIRECTOR FOR MEDICAL AND CLINICAL AFFAIRS
What do you love about living in Croatia?
Croatia’s breathtaking beauty, vibrant culture, and warm community make it special. Living in Zagreb, I enjoy easy access to the seaside, mountains, and forests.
What was your childhood dream job?
I always dreamed of being a teacher because of the inspiration from great educators. Their passion for sharing knowledge certainly influenced my life.
Why laboratory medicine?
I have always been fascinated by the human body and knew that I wanted to help others, so I was certain my future job would involve medicine. I wanted a career that combined my love for science and medicine, and laboratory medicine turned out to be the perfect path.
What life lesson has your career taught you?
Continuous learning is key. Seize every opportunity to expand your knowledge—it’s invaluable for personal and professional growth. Knowledge is something that no one can take away from you.
We are thrilled to have Ana-Maria’s leadership and vision guiding our efforts at Greiner Bio-One.
PREANALYTICAL MYSTERIES
As discussed in the first section, gel separators create a barrier between serum or plasma and red blood cells during centrifugation. This separation occurs due to the specific densities of each component (plasma/serum, gel separator, and RBCs). Gel separator tubes offer many advantages in the fast-paced laboratory environment. However, for some patients, these tubes may not be the optimal choice.
Conditions such as hyperproteinemia can increase the density of plasma or serum. A case study published in the International Journal of Medical Biochemistry describes a patient who was admitted to a public hospital in Turkey [1]. The patient was drawn in a VACUETTE® CAT Serum Separator Clot Activator tube and centrifuged at 1500 g for 10 minutes. Following centrifugation, the gel unexpectedly formed above the serum (see image). This was caused by the patient’s elevated protein concentration of 147 g/L, which increased the density of the serum and altered the gel’s positioning.
Patients with hyperimmunoglobulinemia (elevated IgG levels) or those injected with iodinated radiologic contrast media may also experience this anomaly [2].
SOURCES
1. Atypic separator gel flotation in blood collection in patient with hyperproteinemia. Yasar, Nesibe Esra, and Konukoglu, Dildar, International Journal of Medical Biochemistry 2020; 3(3):186-8. DOI: 10.14744/ijmb.2020.53824.
2. Contradictory Phenomenon Between Serum Separator Tube and Plasma Tube: A Case Report. Pang, Lu, Xing, Ying, Xing, Lingsheng, Miao, Linzi, An, Chongwen, and Li, Haixia.
