法国Biocytex 
法国BIOCYTEX公司建立于20世纪90年代初，多年来一直致力于流式细胞术检测试剂的研究，并已取得了突破性进展，目前已有成熟的产品面市，其产品的特点包括：血小板分析使用全血样本进行检测；样本处理过程中不会引起血小板激活；全程免洗；样本用量少；操作简便、快捷；采用独特的定量技术，可以准确定量细胞表面特定蛋白分子或受体的数量。
法国BIOCYTEX公司研发的一系列关于血小板方面的定量流式全血细胞检测试剂盒，对监控抗血小板药物和协助诊断血小板错乱疾病起到了积极作用。而同样的定量检测技术也应用于白细胞和红细胞受体分析，这些试剂盒的生产对阵发性睡眠症（PNH）提供诊断标准。
目前公司产品主要由一下几类组成：应用于流式细胞术17类（其中血小板10种），用于分子生物学5类，ELISA试剂盒3类（包括检测重组细胞因子CD146），抗体共计56种，其中CD抗体共有49种。
   

Since the foundation of Biocytex in the early 90's in the close proximity of the University and Hospital Complex of La Timone / La Conception in Marseille (France), the need of standardization in flow cytometry analysis still remains a topic of concern. Inter-laboratory reproducibility, day to day reproducibility and positivity and/or negativity threshold determination are a real need that can be addressed by the use of quantitative flow cytometry application kits. This is the expertise offered by Biocytex. We spent 7 years developing and tuning our quantitative flow cytometry technology. After the success of our first generation of products with the QIFIKIT, we introduced our PLATELET kits, a comprehensive line of no wash whole blood flow cytometry kits for the monitoring of antiplatelet drugs (PLATELET VASP/P2Y12) as well as the diagnosis of platelet disorders (PLATELET Gp/Receptors).
The same quantitative technology was applied to the development of kits for leukocyte and red cell receptor analysis (CELLQUANT / REDQUANT kits). A major application is offered for the standardized diagnosis of Paroxysmal Nocturnal Hemoglobinuria (PNH).
In the past two years, the aim of BioCytex was to increase its range of products in the field of Thrombosis and Haemostasis.

Quantitative flow cytometry technology

On a small sample volume containing few cells and heterogeneous cell populations, flow cytometry allows to analyze with high sensitivity the cell size, its contents and the intensity of these stained cells.
Although in current practice of immunophenotyping flow cytometers are mainly used to differentiate positive and negative staining of cells, BioCytex uses these same instruments to quantitate molecules bound on cells, receptors, ligands or drugs as well as intracellular targets.

How does quantitative flow cytometry work ?

Quantitative flow cytometry is achieved by comparing fluorescence intensity and a calibration standard.
BioCytex uses a calibrator made of a mix of bead populations . These calibration beads are coated with known and increasing numbers of immunoglobulins (IgG) bound to their surface thus mimicking the binding of specific monoclonal antibodies to the biological sample cells.
Then, this calibrator and the target stained cells are incubated with polyclonal antibodies labeled with FITC fluorochrome. The beads bear specific number of sites and will allow to draw a calibration curve relating mean fluorescence intensity into a number of receptors per cell. The mean fluorescence intensity (MFI) of the tested sample is reported on the calibration curve to determine the number of molecules expressed per cell. Non specific staining is evaluated using an irrelevant antibody (negative isotypic control).