Development of a stable lipoprotein diluent for use in reconstituting lyophilized human serum for the preparation of clear, hyperlipidemic quality-control materials.

Abstract We describe a simple system for the preparation of a hyperlipidemic control serum. Beta- and pre-beta-lipoproteins are removed from the serum and prepared as a stable diluent; the extracted serum is then lyophilized. Upon addition of the lipoprotein diluent, which was observed to contain only liproprotein and sodium bicarbonate, the serum reconstitutes rapidly, usually within 5 min. By a suitable adjustment of the lipoprotein concentration in the diluent, a hyperlipidemic control serum may be produced with desired concentrations of lipids. Because the lipoproteins are not included in the destructive lyophilization step, the resulting product has remarkable clarity, precision, and stability.

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Preparation and evaluation of laboratory quality control materials for the detection of IgG anti-A/B

LaboratoriumsMedizin ◽

10.1515/labmed-2016-0029 ◽

2016 ◽

Vol 40 (6) ◽

Author(s):

Zhang Min ◽

Lu Hui-Xia ◽

Xie Bo ◽

Xin Qi

Keyword(s):

Quality Control ◽

Repeated Measurements ◽

Quality Controls ◽

Assay Procedure ◽

Control Serum ◽

Quality Control Materials ◽

Control Survey ◽

Accuracy Of Measurement ◽

The Mean ◽

Preparation And Evaluation

AbstractBackground:This research was aimed at preparing laboratory quality control materials for the detection of IgG anti-A/B and evaluating them in preliminary applications.Methods:Mixed IgG anti-A and anti-B sera were used as quality controls for measuring IgG anti-A/B titers. The quality control materials were packaged with sodium azide as preservative, and stored at –30°C. Twenty repeated measurements were done in succession. After the quality control values were determined, the quality control materials were used preliminarily. Quality controls and the untested blood samples were assayed at the same time within 6 months.Results:The mean IgG anti-A titer of the high-value quality control serum was 1:550 and ranged from 1:225 to 1:1100 for the control. The mean IgG anti-B titer of the high-value quality control serum was 1:269 and ranged from 1:135 to 1:538 for the control. The mean IgG anti-A and B titer of the low-value control serum was 1:32, with a quality control range of 1:16–1:64.Conclusions:Laboratory quality control materials in the measurement of IgG anti-A/B titers were developed successfully. Standardization of the assay procedure and quality control survey would be necessary for the accuracy of measurement.

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Long-term stability of a stabilized liquid quality-control serum.

Clinical Chemistry ◽

10.1093/clinchem/27.8.1448 ◽

1981 ◽

Vol 27 (8) ◽

pp. 1448-1452 ◽

Cited By ~ 10

Author(s):

A E Hartmann ◽

R D Juel ◽

R N Barnett

Keyword(s):

Quality Control ◽

Linear Regression ◽

Linear Regression Analysis ◽

Linear Regression Coefficient ◽

Term Stability ◽

Long Term Stability ◽

Control Serum ◽

Quality Control Materials ◽

Refrigerator Temperature

Abstract To evaluate the long-term stability of a new liquid quality-control serum ("Decision", Beckman Instruments, Inc.) stabilized with ethylene glycol (330 mL/L), we analyzed it for 22 commonly measured analytes during storage at 2--8 degrees C for 24 days or -15 to -20 degrees C for 55 weeks. Three separate laboratories replicated the analyses, using various analytical methodologies. The data were subjected to linear regression analysis, regressing concentration on time. Analytes were considered unstable when the linear regression coefficient was unequal to zero with 95% or greater probability in all three laboratories. By this criterion all of the analytes were stable for at least 24 days when the control serum was stored at refrigerator temperature and for at least 55 weeks at freezer temperature. We conclude this material is a satisfactory substitute for existing lyophilized quality-control materials and offers certain advantages: stability, vial-to-vial uniformity, decreased waste, and eliminated reconstitution.

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Quality of Commercially Available Controls in Laser Immunonephelometry

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456328001700403 ◽

1980 ◽

Vol 17 (4) ◽

pp. 178-182 ◽

Cited By ~ 7

Author(s):

Gerald Shulman

Keyword(s):

Quality Control ◽

Reference Sample ◽

Radial Immunodiffusion ◽

Mean Values ◽

Serum Pool ◽

Control Serum ◽

Specific Proteins ◽

Quality Control Materials ◽

Working Standards

Lack of accuracy in expressing concentrations of specific proteins in different lots of Hyland calibrating reference and quality control materials, supplied for the Hyland PDQ laser nephelometer, prompted an attempt to find alternative and more reliable calibrating materials available commercially. Laser grade (Atlantic Antibodies) and radial immunodiffusion grade materials (Behring Diagnostics) were evaluated in this study. Using Atlantic Antibodies' calibrator, only five of 11 specific proteins assayed in Atlantic control serum were within acceptable ranges; precision was less than that using Hyland materials of identical lots. Mean values for each of 10 of the same 11 specific proteins of Behring control plasma, assayed against Behring stabilised human serum, were within manufacturers' acceptable ranges; however, precision was less than that with Hyland materials from identical lots. Nine of the 11 specific proteins in a frozen serum pool sample, measured on the laser nephelometer, agreed well with results of the specific proteins measured by radial immunodiffusion, using the same Behring calibration and quality control. Only the Hyland materials were prediluted for use, which explains the greater precision that was obtained. Intercomparison of concentrations, as expressed by respective manufacturers, was largely unacceptable. Based on these results there is need, until satisfactory reagents become available, to standardise on one parent Hyland reference sample giving best precision and to calibrate all subsequent working standards against the parent reference.

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In Reply: Limitations to Quality Control Materials for CO-oximeters

CHEST Journal ◽

10.1378/chest.87.3.409-c ◽

1985 ◽

Vol 87 (3) ◽

pp. 409-410

Author(s):

John R. Spurzem ◽

John W. Shigeoka ◽

H. William Bonekat

Keyword(s):

Quality Control ◽

Quality Control Materials

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Suitability of quality control materials for prostate-specific antigen (PSA) measurement: inter-method variability of common tumor marker control materials

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2012-0660 ◽

2013 ◽

Vol 51 (4) ◽

Cited By ~ 1

Author(s):

Zivjena Vucetic ◽

Ann Dnistrian ◽

Olle Nilsson ◽

Hans G. Lilja ◽

Mario Plebani

Keyword(s):

Quality Control ◽

Tumor Marker ◽

Prostate Specific Antigen ◽

Specific Antigen ◽

Quality Control Materials

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A Questionnaire Survey of Quality Control of Flow Cytometry in Korea and Development of New Quality-Control Materials

Journal of Laboratory Medicine and Quality Assurance ◽

10.15263/jlmqa.2017.39.4.168 ◽

2017 ◽

Vol 39 (4) ◽

pp. 168-177

Author(s):

Jae Seong Shim ◽

Sang Mi Hwang ◽

In Suk Kim ◽

Sang Yong Shin ◽

Ju Young Oh ◽

...

Keyword(s):

Flow Cytometry ◽

Quality Control ◽

Questionnaire Survey ◽

Quality Control Materials ◽

Control Of Flow

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1337. Development, Maintenance, and Application of Opsonophagocytic Assays to Measure Functional Antibody Responses to Support a 20 Valent Pneumococcal Conjugate Vaccine

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1201 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S484-S484

Author(s):

Ingrid L Scully ◽

Mark W Cutler ◽

Seema Gangolli ◽

Todd Belanger ◽

David Cooper ◽

...

Keyword(s):

Quality Control ◽

Antibody Responses ◽

Antibody Activity ◽

Pneumococcal Vaccines ◽

Next Generation ◽

High Quality ◽

Assay Performance ◽

Control Serum ◽

Serological Data ◽

Over Time

Abstract Background Opsonophagocytic assays (OPAs) are an important tool for assessing vaccine-induced functional antibody responses. OPAs are complex assays composed of many biological components (eg serum, complement sources, bacteria, and human phagocytes) which contribute to assay variability and may result in titer drift if not carefully controlled. Rigorous development and validation coupled with routine monitoring of assay performance are required to ensure that high-quality OPA serological data are consistently generated throughout the lifetime of existing and next-generation pneumococcal vaccines. Methods OPA specificity was demonstrated by competing functional antibody activity with pneumococcal polysaccharides. Assay qualification/validation assessed accuracy, precision, and sample linearity. Assay performance over time was assessed through the implementation of quality control serum data tracking systems and longterm serum proficiency panels that are routinely tested during assay performance. Human quality control sera are included on each assay plate to ensure that each plate meets pre-specified acceptance criteria. Proficiency serum panels are comprised of individual human serum samples derived from subjects immunized with pneumococcal vaccines and are used to monitor performance across a range of serological titers and over time. Results The OPAs were shown to be specific and reproducible. Monitoring of assay performance over time demonstrated that the assays are stable. For the 13 serotypes contained in 13vPnC reliable titers have been generated in over a decade of testing which is an essential prerequisite in the evaluation of next-generation pneumococcal conjugate vaccines such as 20vPnC, whose licensure depends on demonstration of non-inferiority to 13vPnC. Conclusion Maintenance and careful monitoring of high-quality assays to measure functional antibody responses, such as OPAs, is critical for the delivery of reliable serological data to support the advancement of pneumococcal vaccine programs. Pneumococcal OPAs must be rigorously maintained to ensure continuity of serological data over time and inform licensure decisions of next-generation vaccines as well as postmarketing and seroepidemiology studies. Disclosures All authors: No reported disclosures.

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Quality-control materials for use with monitors of blood glucose.

Clinical Chemistry ◽

10.1093/clinchem/34.1.212 ◽

1988 ◽

Vol 34 (1) ◽

pp. 212-212 ◽

Cited By ~ 2

Author(s):

J Stejskal ◽

M A Wendland

Keyword(s):

Quality Control ◽

Blood Glucose ◽

Quality Control Materials

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Improved assessment of plasma lipoprotein patterns. IV. Simple preparation of a lyophilized control serum containing intact human plasma lipoproteins.

Clinical Chemistry ◽

10.1093/clinchem/28.6.1335 ◽

1982 ◽

Vol 28 (6) ◽

pp. 1335-1337 ◽

Cited By ~ 18

Author(s):

H Wieland ◽

D Seidel

Keyword(s):

Human Serum ◽

Human Plasma ◽

Clinical Chemistry ◽

Plasma Lipoprotein ◽

Plasma Lipoproteins ◽

Simple Preparation ◽

Control Serum

Abstract Addition of sucrose (413-825 mmol/L) to human serum allows plasma lipoproteins to be lyophilized without denaturation. A control serum so prepared is especially suited for use in monitoring determinations of apolipoproteins and quantitative lipoprotein electrophoresis. It is clear upon reconstitution; hence, the described procedure may also be useful for preparation of control sera for general clinical chemistry without de-lipoproteinization.

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