Alkaline Phosphatase Activity in Lyophilised Quality Control Serum

1979 ◽  
Vol 16 (1-6) ◽  
pp. 271-274 ◽  
Author(s):  
D. G. Bullock ◽  
F. M. McSweeney ◽  
H. Saidi ◽  
T. P. Whitehead
Keyword(s):  
Quality Control ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Storage Temperature ◽  
Quality Control Material ◽  
External Quality Control ◽  
Control Material ◽  
External Quality ◽  
Control Serum

The rise in alkaline phosphatase activity has been studied after reconstitution of 16 commercial preparations of lyophilised quality control material. The effects of storage temperature and analytical method on the rise in activity have also been studied, with a view to producing a reconstitution protocol suitable for recommendation to participants in external quality control surveys. Great differences were found in the magnitude of this rise in activity; these differences can be reduced to negligible levels if the material is mixed for 30 minutes at ambient temperature after reconstitution and then stored for not more than 4 hours at 4°C before assay.

Protective effect of glycerol against the increase in alkaline phosphatase activity of lyophilized quality-control serum.

1977 ◽  
Vol 23 (10) ◽  
pp. 1873-1877 ◽  
Author(s):  
K Tanishima ◽  
Y Minamikawa ◽  
N Yokogawa ◽  
M Takeshita
Keyword(s):  
Quality Control ◽  
Alkaline Phosphatase ◽  
Ethylene Glycol ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Maximum Activity ◽  
Freezing And Thawing ◽  
Practical Applications ◽  
Control Serum ◽  
Repeated Freezing

Abstract We studied the effectiveness of glycerol or ethylene glycol in preventing the increase in alkaline phosphatase activity of lyophilized or refrigerated quality-control serum after reconstitution or repeated freezing and thawing. Control serum reconstituted completely from the lyophilized state with subsequent storage at -20 degrees C showed a considerable decrease in alkaline phosphatase activity immediately after thawing, and a gradual increase in activity on allowing it to stand at room temperature. Adding glycerol or ethylene glycol to the reconstituted serum obviated these changes in activity, glycerol being more effective than ethylene glycol. Reconstituted serum with added glycerol maintained maximum activity before refrigeration during either storage for 30 days or on repeated freezing and thawing. Practical applications of this glycerol-supplemented control serum are discussed.

scholarly journals Performance of the Boditech iCHROMA Covid-19 IgG antibody assay with the external quality control for UK NIBSC (National Institute of Biological Standards and Control)

2020 ◽  
Vol 2 (8) ◽  
pp. 01-04
Author(s):  
J Bolodeoku Bolodeoku
Keyword(s):  
Quality Control ◽  
Quality Control Material ◽  
External Quality Control ◽  
Antibody Assay ◽  
Igg Antibody ◽  
Control Material ◽  
External Quality ◽  
The Uk ◽  
And Control ◽  
Control Samples

Background: There is a need for laboratories to participate in EQA schemes to achieve a harmonization of test results and to improve serological testing and research on COVID-19 and SARS-CoV-2. The Boditech iCHROMA point of care immunoassay analyser has a Covid-19 antibody assay for the qualitative determination of IgG antibodies in human whole blood/serum/plasma. The National Institute for Biological Standards and Control (NIBSC) in the United Kingdom has a portfolio of reference and research reagents, including reagents for EQA that are available to laboratories to help them set up and develop accurate diagnostic tests for SARS-CoV-2 assays. Objectives: To determine the performance of the Boditech iCHROMA Covid-19 IgG antibody assay using the external quality control material provided by the UK NIBSC (National Institute for Biological Standards and Control). Results: The Boditech iCHROMA Covid-19 IgG assay using the cut off index >1.1, reported the results of the 33 positive control samples as positive with index range from 19.50 – 29.00, with a mean of 23.75 and standard deviation of SD of 2.53. It also reported the results of the 33 negative control samples as negative with an index range of 0.00 for all samples. Conclusion: The performance of the Boditech iCHROMA Covid-19 IgG antibody assay using external quality control material from the UK NIBSC was very good, confirming the precision of the Boditech iCHROMA Covid 19 IgG antibody method.

Possible Mechanisms for the Increase in Alkaline Phosphatase Activity of Lyophilized Control Material

1972 ◽  
Vol 18 (12) ◽  
pp. 1518-1523 ◽  
Author(s):  
Alistair F Smith ◽  
Barbara A Fogg
Keyword(s):  
Molecular Weight ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Gel Filtration ◽  
Low Molecular Weight ◽  
Temperature Dependent ◽  
Control Material ◽  
Rate Of Increase ◽  
Control Procedures

Abstract The increased alkaline phosphatase (EC 3.1.3.1) activity of reconstituted lyophilized control sera has recently been the focus of considerable interest because of its possible implications for quality-control procedures. We confirm that these reconstituted materials show a temperature-dependent increase in alkaline phosphatase activity, but could show no alteration in activity of fresh sera. The rate of increase in activity was unaffected by dialysis of the reconstituted material, and occurred more rapidly in dilute solutions. Studies with acrylamide gel electrophoresis and Sephadex G-200 gel filtration showed that, immediately after reconstitution, a high-molecular-weight alkaline phosphatase component predominated; during subsequent spontaneous activation this component decreased, and there was a concomitant increase in a low-molecular-weight alkaline phosphatase component. The results obtained when the reconstituted material was extracted with butanol suggest that the observed changes in alkaline phosphatase activity may be attributed to the breakdown of a complex between alkaline phosphatase and lipoprotein.

scholarly journals Питання зовнішнього контролю якості лабораторних досліджень на сифіліс у лікувальних закладах України

2021 ◽  
pp. 15-19
Author(s):  
V. V. Kutova ◽  
◽  
Ya. F. Kutasevych ◽  
O. N. Belokon ◽  
T. V. Degtyar ◽  
...  
Keyword(s):  
Quality Control ◽  
High Efficiency ◽  
Rapid Test ◽  
Random Errors ◽  
External Quality Control ◽  
Serum Samples ◽  
External Quality ◽  
Serological Tests ◽  
Control Serum ◽  
Comparative Results

The objective of the work is to identify systemic and random errors in the formulation of controlled methods and to achieve comparative results obtained by laboratories participating in external quality control of laboratory tests for syphilis. Materials and methods. Laboratories of three levels took part in the activities of external quality control of serological diagnostics of syphilis: clinical diagnostic laboratories (CDL) of medical institutions of scientific research institutes of the NAMS of Ukraine, serological departments as part of the CDL of the dermatovenerological profile of the RDVD, CDVD. Results. The quality of serological tests for syphilis in 21 CDL (serological departments) was assessed using the following methods: RMP, RPR, Rapid-test, TPHA, FTA-abs, ELISA in three control serum samples according to formal and essential characteristics. The most significant differences in the results were revealed in the study of control serum samples with a low content of antibodies and those without antibodies to the causative agent of syphilis in the non-treponemal RMP test and the treponemal FTA-abs test. Conclusions. The conducted studies have shown the high efficiency of the practical application of the developed system of external quality control of laboratory methods for diagnosing syphilis.

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