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Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
A collaborative study to establish the 7th International Standard for Factor VIII Concentrate
1Division of Haematology and Informatics Laboratory, National Institute for Biological Standards and Control, Potters Bar, Hertfordshire, UK. araut@nibsc.ac.uk
Journal of Thrombosis and Haemostasis : JTH
|January 7, 2005
Summary
Preparation N was evaluated as a potential replacement for the International Standard for Factor VIII Concentrate. It was found to be stable and suitable, officially becoming the 7th International Standard.
Area of Science:
- Biotechnology
- Hematology
- Pharmaceutical Science
Background:
- Established standards are crucial for accurate Factor VIII concentrate quantification.
- Preparation N (NIBSC 99/678) was developed as a candidate for the next International Standard.
Purpose of the Study:
- To evaluate Preparation N as a potential replacement for the WHO 6th International Standard for Factor VIII Concentrate.
- To determine the potency and stability of Preparation N through a collaborative study.
Main Methods:
- A collaborative study involving 38 laboratories assessed Preparation N against four established Factor VIII concentrate standards.
- Assays were performed using both one-stage and chromogenic methods, adhering to ISTH/SSC recommendations.
- Accelerated degradation studies were conducted to assess the stability of Preparation N.
Main Results:
- Good agreement was observed between laboratories for both assay methods (one-stage and chromogenic), with potencies differing by less than 2%.
- Potencies varied relative to different standards, ranging from 10.1 to 11.4 IU per ampoule.
- Preparation N demonstrated high stability, with a predicted annual activity loss of less than 0.001% at -20°C.
Conclusions:
- Preparation N (NIBSC 99/678) was accepted as the 7th International Standard for Factor VIII Concentrate with an assigned potency of 11.0 IU per ampoule.
- The candidate standard is highly stable and suitable for its intended purpose.
