Related Experiment Video
Updated: Jun 2, 2026
08:42
Challenges in Rheological Characterization of Highly Concentrated Suspensions — A Case Study for Screen-printing Silver Pastes
Published on: April 10, 2017
Influence of using a roller mixer on rejected samples in coagulation tests
1Clinical Biochemistry Laboratory, Ministry of Health Istanbul Research and Training Hospital, Istanbul, Turkey. drhalearal@yahoo.com
International Journal of Laboratory Hematology
|May 17, 2011
Summary
Using a roller mixer after blood collection significantly reduces rejected coagulation test samples. This simple preanalytical step improves laboratory accuracy and test result reliability.
Area of Science:
- Clinical Pathology
- Laboratory Medicine
- Preanalytical Phase Optimization
Background:
- Coagulation tests are crucial for diagnosing and monitoring various medical conditions.
- High rejection rates of blood samples in coagulation testing can lead to delayed diagnoses and increased healthcare costs.
- Standardization of preanalytical procedures is essential for ensuring accurate laboratory results.
Purpose of the Study:
- To evaluate the impact of using a roller mixer immediately after blood collection on the rejection rate of coagulation test samples.
- To determine if roller mixer use improves the reliability of preanalytical sample handling for coagulation assays.
Main Methods:
- A retrospective study comparing two groups of blood samples collected for prothrombin time (PT) testing.
- Group I: Manual inversion of blood collection tubes.
- Group II: Blood collection tubes placed on a roller mixer at 30 rpm immediately after collection. Statistical comparison using chi-square analysis.
Main Results:
- The rejection rate of coagulation samples significantly decreased from 0.79% in the manual inversion group (Group I) to 0.20% in the roller mixer group (Group II).
- This represents a substantial reduction in sample rejection attributed to the use of a roller mixer (P<0.001).
Conclusions:
- Implementing roller mixer use post-blood collection is a recommended practice to enhance the reliability of coagulation testing.
- Standardizing the preanalytical phase through roller mixer application can effectively minimize laboratory errors and ensure the accuracy of coagulation test results.
Related Concept Videos
01:06Coagulation
Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and...
01:09Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
01:12Precipitation Processes
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...