Preparation And Evaluation Of The Whole Blood Quality Control Material For CD34~+Cell Enumeration

Objective:To improve the capability and quality of laboratory hematopoietic stem cell enumeration, and ensure the accuracy and comparability of hematopoietic stem cell enumeration results, the clinical laboratory must carry out internal quality control(IQC) and take part in external quality assessment(EQA). The quality control materials are needed in IQC and EQA. However, at present, there is no domestic manufacture to produce such quality control materials in China; the supply of quality control materials rely on foreign manufacturers (such as Beckman-Coulter company, BD company, Inc.). Unfortunately, the imported quality control materials have defects: expensive, short term of validity, complicated import procedures, and poor applicability, etc. Therefore, IQC and EQC are limited. To promote IQC and EQC, after referencing a large number of literature and patents, the National Center of Clinical Laboratory intended to develop the whole blood quality control materials for hematopoietic stem cell enumeration with fresh human umbilical cord blood; and to evaluate its homogeneity and stability.Methods1. Found out the influence factors on the preparation of the whole blood quality control materials for hematopoietic stem cell enumeration, and after many experiments, established the best appropriate approach to prepare the control materials. Successfully prepared two lots of the whole blood quality control materials for hematopoietic stem cell enumeration.2. According to CNAS-GL03(Guidance on Evaluating the Homogeneity and Stability of Samples Used for Proficiency Testing) and ISO Guide35(Reference material-General and Statistical principles for certification), the homogeneity and stability of the prepared quality control materials for hematopoietic stem cell enumeration were evaluated; and the related imported quality control materials were simultaneously evaluated for comparison.Results1. Fresh cord blood provided by the Beijing China Cord Blood Bank were selected to prepare quality control material.2. The2concentration of B fixed liquid was selected to prepare quality control material.3. The results of erythrocyte lysis ability evaluation of the prepared quality control materials showed that, after dealing with two kinds of common lysis agents, there is no visible red sediment at the bottom of the tubes; and leukocyte scatter plot showed clear clustering of nucleated cells; and there is no red blood cells and cell debris interference.4. The results of the homogeneity evaluation of the prepared quality control materials showed that the difference of the within groups and between groups was insignificant (P>0.05). The coefficient variation(CV) of homogeneity for20111101and20111110lots of prepared quality control materials were5.40%and6.12%. The uncertainty of homogeneity for20111101and20111110lots of prepared quality control materials were0.004%and0.003%.5. A linear regression based on the stability evaluation of8weeks indicated that the linear trend was insignificant (P>0.05). The uncertainty of long-term stability for20111101and20111110lots of prepared quality control materials and imported quality control materials were0.023%,0.015%and0.012%respectively. 6. The control materials were applied on BD-FACSCalibur and Coulter-EPICS XL flow cytometry. The different kinds of nucleated cells divided from each other very well, and the positive cells can be devided very well from negative cells. The deviation of FS-1lot of prepared quality control materials on BD-FACSCalibur and Coulter-EPICS XL flow cytometry were5.73%and4.54%; and the deviation of FS-2lot of prepared quality control materials on BD-FACSCalibur and Coulter-EPICS XL flow cytometry were6.72%、3.50%.7. The internal quality control test application results showed that the CV of20111101and20111110lots of quality control materials and imported of quality control test results were2.02%,1.24%and0.94%respectively.Conclusion:The prepared whole blood quality control materials for hematopoietic stem cells enumeration have a good performance on the homogeneity and stability with the shelf life of8weeks at least. The control materials are applicable to BD-FACSCalibur and Coulter-EPICS XL flow cytometry, and can be used for quality control in hematopoietic stem cells enumeration by flow cytometry.