ABSTRACT
Objective To prepare a liquid composite quality control material of D-dimer,and then to inves-tigate its stability.Methods Pooled human serum without infection[negative for the antibodies to human im-munodeficiency virus(HIV),hepatitis C virus(HCV)and hepatitis B surface antigen(HBsAg),TP-IgG]was used as the medium for the composite quality control material preparation to investigate its precision and sta-bility.Results The within-run precision of our product was 1.83% which was < 1/4 CLIA'88 acceptable per-formance range.The between-run precision was 3.02% which was < 1/3 CLIA'88 acceptable performance range.The quality control material was stable for 12 months at -20 ℃.The stability[coefficient of variation (CV%)of each item of the quality control material was<1/2 CLIA'88 acceptable performance range.Conclu-sion T he liquid composite lipid quality control material has good homogeneity and stability,and it can be used for D-dimer testing the internal quality control.
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Objective To prepare freeze-drying control materials of IgG antibody against Schistosoma japonicum for detec-tion kits. Methods The serum samples of schistosomiasis patients from endemic areas and normal people without history of schistosome infection or contact with infested water in Hubei Province were collected.All the sera were detected by the method approved by China Food and Drug Administration and selected for preparation of quality control samples. Results Totally twelve positive quality control materials,ten negative quality control materials,and one sensitive and one precision quality con-trol materials were screened.According to the positive serum level,the positive degrees of quality control materials were divided into strong,medium and weak levels.The stability could be valid for one year.Conclusions The freeze-drying quality control materials of IgG antibody against S.japonicum for detection kits are prepared.They are easy to use and have good stability,and therefore,they may meet the requirement of quality control for the detection of schistosomiasis diagnostics kits.
ABSTRACT
BACKGROUND: Because of a lack of quality control (QC) materials, stool examination has not been standardised. This study examined intestinal parasites in diarrhea specimens to manufacture and evaluate the performance stability of QC materials for stool examination. METHODS: This study examined diarrhea specimens submitted for stool culture. Microscopic examination was performed using the direct smear and formalin-ether concentration method (Military General Laboratory, MGL). Enzyme-linked immunosorbent assay (ELISA) kits (R-Biopharm AG, Germany) and xTAG Gastrointestinal Pathogen Panel (Luminex Corp., USA) were used for the three major protozoa: Cryptosporidium parvum, Giardia lamblia, and Entamoeba histolytica. Polymerase chain reaction (PCR) was performed for Dientamoeba fragilis and Blastocystis hominis. The QC materials for stool examination were generated using Diphyllobothrium nihonkaiense ova. The manufactured QC materials were evaluated under different storage conditions, with varying preservatives, temperatures, and storage times. RESULTS: From November 2015 to April 2016, 82 diarrhea specimens were collected and tested. All results from microscopy and ELISA were negative; C. parvum (n=2) and G. lamblia (n=1) were detected by xTAG, while D. fragilis (n=10) and B. hominis (n=2) were detected by PCR. High- and low-concentration QC materials were manufactured. Using the high-concentration QC material, ova were observed in all storage conditions using MGL. Using the low-concentration QC material, the ova were observed until 14 days, but not after 3 weeks. CONCLUSIONS: It should be considered for making QC materials for stool examinations that focus on D. fragilis and B. hominis frequently found in Korea and with the caution to the low-concentration of QC materials could be unstable.
Subject(s)
Blastocystis hominis , Cryptosporidium parvum , Diarrhea , Dientamoeba , Diphyllobothrium , Entamoeba histolytica , Enzyme-Linked Immunosorbent Assay , Giardia , Giardia lamblia , Korea , Methods , Microscopy , Ovum , Parasites , Polymerase Chain Reaction , Quality ControlABSTRACT
BACKGROUND: Since various hematology analyzers apply common or different principles in complete blood counting, difference between measured values could developed according to the control material used in external quality assessment. Diagnostic Hematology Subcommittee has been using formalin fixed blood and Liquichek(TM) Hematology-16 (Bio-Rad, USA) as control material of external quality assessment alternately but recently significant difference of test results was found in some analyzers. We intended to select adequate control material showing similar test results in most analyzers. METHODS: Using fresh whole blood, formalin fixed blood, Liquichek(TM) Hematology-16 and CBC-4K (R&D, USA), 5 parameters (WBC, RBC, Hb, Hct, platelet) were measured in 4 hematology analyzers; CELL-DYN sapphire (Abbott Diagnostics, USA), Coulter LH750 (Beckman Coulter, USA), ADVIA 2120 (Siemens Diagnostics, USA) and Sysmex XE-2100 (Sysmex Co., Japan). Linearity, within-run precision and between-day precision of 4 materials for each parameter were evaluated at different analyzers. RESULTS: The between-day precisions for WBC of formalin fixed blood showed very high CVs of 6.5~13.5% in all 4 hematology analyzers. The within-run and between-day precisions for WBC and platelet of Liquichek(TM) Hematology-16 showed high CVs of 9.3%, 16% and 19.8%, 18%, respectively in CELL-DYN analyzer. But, CBC-4K showed a good linearity (r2=0.9953~0.9993) and precision (within-run CVs, 0~1.5% and between-day CVs, 0~2.0%) in all analyzers. CONCLUSIONS: Fresh whole blood, formalin fixed blood and Liquichek(TM) Hematology-16 are not appropriate for standardization of external quality control materials because of some different test results among analyzers. We conclude that CBC-4K with good performance in all hematology analyzer is adequate as external quality control material.