Two-dimensional centrifugation for desk-top clinical chemistry.

1985 ◽  
Vol 31 (9) ◽  
pp. 1457-1463 ◽  
Author(s):  
S G Schultz ◽  
J T Holen ◽  
J P Donohue ◽  
T A Francoeur
Keyword(s):  
Whole Blood ◽  
Vision System ◽  
Clinical Chemistry ◽  
Spectrophotometric Analysis ◽  
Optical Measurements ◽  
Flash Lamp ◽  
Microprocessor Control ◽  
Serum Samples ◽  
Mixing Chambers ◽  
Clinical Chemistry Tests

Abstract We have developed a new system for clinical chemistry analysis, the Vision System, in which centrifugal force is used to separate whole blood, measure reagent and plasma volumes, and complete all steps required for a spectrophotometric analysis. The system is based on use of a multichambered plastic test pack containing liquid reagents, which can be centrifuged at 500 X g in two planes, oriented at right angles to each other. Alternating centrifugal fields allows liquid reagents and plasma to flow into highly precise measuring and mixing chambers. A unique flash lamp and diode array spectrometer provide for optical measurements of 10 test packs at as many as eight wavelengths simultaneously. The temperature of each individual test pack is controlled by using a flash lamp coupled to a liquid crystal temperature sensor. Microprocessor control allows as many as 10 different chemistry reactions to be measured simultaneously on whole-blood, plasma, or serum samples. Comparison with results by an established batch-photometric analyzer demonstrated excellent precision and accuracy for various clinical chemistry tests.

High dose ascorbic acid treatment in COVID-19 patients raised some problems in clinical chemistry testing

2020 ◽  
Vol 45 (5) ◽  
pp. 491-498
Author(s):  
Fatih Yesildal ◽  
Ferruh Kemal Isman
Keyword(s):  
Ascorbic Acid ◽  
Ldl Cholesterol ◽  
Clinical Chemistry ◽  
Assay Method ◽  
High Dose ◽  
Serum Samples ◽  
Choice Of Treatment ◽  
High Concentrations ◽  
Clinical Chemistry Tests ◽  
Abbott Architect

AbstractObjectiveCOVID-19 pandemia still continues to threaten the whole world. High dose ascorbic acid (AA) infusion is a choice of treatment and its efficiency is still being investigated. AA interferes with many clinical chemistry tests. However, data about the interference of high concentrations of AA is not sufficient. In this study, we aimed to investigate the interference of AA at high concentrations on commonly used chemistry assays.Materials and MethodsSerum samples at AA concentrations of 200, 150, 100, 75, 50, 25, 10, 5, 2 and 0 mg/dL were prepared by using the stock solution of 15000 mg/dL AA. Each sample was analyzed by using the most common 30 chemistry tests (Abbott Architect C8000, Illinois, USA) and a POCT glucometer (STANDARD GlucoNavii, Gyeonggi-do, Republic of Korea).ResultsCreatinine, sodium and glucose (POCT) tests were found to be positively interfered by increasing AA concentrations; while direct bilirubin, lipase, UIBC, triglyceride, total cholesterol, HDL/LDL cholesterol tests were negatively interfered. Absolute interference (%) increased as the AA concentration increased.ConclusionThis is the largest and first study to investigate the interference of high dose AA, which is used in severe COVID-19 patients nowadays. Manufacturers and clinicians should be aware of the possibility of aberrant results due to high dose AA infusion. Clinicians should not forget to consult a laboratory specialist, since he is the only person to monitor the reactions in all assays, and know the technical subjects like interferences, assay method specifications. This issue is very important for correct decision-making and interpretation of the data-mining studies accurately and efficiently.

scholarly journals Gentamicin and Vancomycin Interference on Results of Clinical Chemistry Parameters on Abbott Architect c8000

2019 ◽  
Vol 143 (6) ◽  
pp. 738-747
Author(s):  
Tina Brencic ◽  
Nora Nikolac
Keyword(s):  
Clinical Chemistry ◽  
Immunoglobulin A ◽  
Direct Bilirubin ◽  
University Hospital ◽  
Serum Samples ◽  
Acceptance Criteria ◽  
Vancomycin Concentration ◽  
Drug Concentrations ◽  
High Concentrations ◽  
Clinical Chemistry Tests

Context.— Gentamicin and vancomycin are nephrotoxic antibiotics. Little is known about the influence of drug concentrations on results of clinical chemistry tests. Objective.— To investigate gentamicin and vancomycin interference on results of 33 commonly measured biochemistry tests. Design.— The study was carried out in the University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice (Zagreb, Croatia). For each drug, 10 aliquots of pooled serum were prepared. In order to cover toxic concentrations, pool serum samples were spiked with drugs to obtain 0 to 50 μg/mL of gentamicin and 0 to 200 μg/mL of vancomycin. Biochemistry tests were measured in duplicate on the Architect c8000 analyzer, and drug concentrations were measured on Architect i2000 SR (both Abbott Laboratories, Abbott Park, Illinois). For each tested concentration, bias was calculated against the initial measurement. Acceptance criteria were defined as measurement uncertainty of the commercial control with the value close to the measured range of the pool sample. Results.— For gentamicin, all bias values were below established criteria. For vancomycin, significant changes were observed for potassium, direct bilirubin, and immunoglobulin A. Significant bias was already detected at low vancomycin concentration (2.98 μg/mL) for direct bilirubin (bias = 9.7%; acceptable = 8%). Potassium bias at the highest vancomycin concentration (204.4 μg/mL) exceeded acceptance criteria (bias = 4.5%; acceptable = 4%). For immunoglobulin A, no apparent trend was observed, and bias is attributed to increased method imprecision. Conclusions.— Gentamicin did not interfere with the results of clinical chemistry tests. Direct bilirubin concentration is falsely increased in the presence of vancomycin, and potassium is affected at high concentrations.

scholarly journals Centrifugation and capillarity integrated into a multiple analyte whole blood analyser

1995 ◽  
Vol 17 (3) ◽  
pp. 99-104 ◽  
Author(s):  
C. T. Schembri ◽  
T. L. Burd ◽  
A. R. Kopf-Sill ◽  
L. R. Shea ◽  
B. Braynin
Keyword(s):  
Whole Blood ◽  
Clinical Chemistry ◽  
Capillary Forces ◽  
Red Cells ◽  
Single Use ◽  
Absorbance Data

A unique clinical chemistry analyser is described which processes 90 μl of whole blood (fingerstick or venous) into multiple aliquots of diluted plasma and reports the results of 12 tests in 14 min. To perform a panel of tests, the operator applies the unmetered sample directly into a single use, 8 cm diameter plastic rotor which contains the required liquid diluent and dry reagents. Using centrifugal and capillary forces, the rotor meters the required amount of blood, separates the red cells, meters the plasma, meters the diluent, mixes the fluids, distributes the fluid to the reaction cuvettes and mixes the reagents and the diluted plasma in the cuvettes. The instrument monitors the reagent reactions simultaneously using nine wavelengths, calculates the results from the absorbance data, and reports the results.

Frequent monitoring of Epstein-Barr virus DNA load in unfractionated whole blood is essential for early detection of posttransplant lymphoproliferative disease in high-risk patients

Blood ◽  
2001 ◽  
Vol 97 (5) ◽  
pp. 1165-1171 ◽  
Author(s):  
Servi J. C. Stevens ◽  
Erik A. M. Verschuuren ◽  
Inge Pronk ◽  
Wim van der Bij ◽  
Martin C. Harmsen ◽  
...  
Keyword(s):  
Whole Blood ◽  
Epstein Barr Virus ◽  
Lymphoproliferative Disease ◽  
Serum Samples ◽  
Barr Virus ◽  
Load Monitoring ◽  
Risk Patients ◽  
Posttransplant Lymphoproliferative Disease ◽  
Ebv Dna ◽  
Epstein Barr

Posttransplant lymphoproliferative disease (PTLD) is a frequent and severe Epstein-Barr virus (EBV)–associated complication in transplantation recipients that is caused by iatrogenic suppression of T-cell function. The diagnostic value of weekly EBV DNA load monitoring was investigated in prospectively collected unfractionated whole blood and serum samples of lung transplantation (LTx) recipients with and without PTLD. In PTLD patients, 78% of tested whole blood samples were above the cut-off value of quantitative competitive polymerase chain reaction (Q-PCR) (greater than 2000 EBV DNA copies per mL blood), with the majority of patients having high viral loads before and at PTLD diagnosis. Especially in a primary EBV-infected patient and in patients with conversion of immunosuppressive treatment, rapid increases in peripheral blood EBV DNA load diagnosed and predicted PTLD. In non-PTLD transplantation recipients, only 3.4% of the whole blood samples was above the cut-off value (P < .0001) despite heavy immune suppression and cytomegalovirus (CMV)-related disease. These findings illustrate the clinical importance of frequent EBV DNA load monitoring in LTx recipients. The increased EBV DNA loads in PTLD patients were restricted to the cellular blood compartment, as parallel serum samples were all below cut-off value, which indicates absence of lytic viral replication. EBV+ cells in PTLD patients have a very short doubling time, which can be as low as 56 hours, thereby creating the need for high screening frequency in high-risk patients. Furthermore, it is shown that EBV and CMV can reactivate independently in LTx recipients and that EBV DNA load monitoring may be useful in discriminating PTLD from rejection.

Methods to reduce lipemic interference in clinical chemistry tests: a systematic review and recommendations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sheila X. Soh ◽  
Tze Ping Loh ◽  
Sunil K. Sethi ◽  
Lizhen Ong
Keyword(s):  
Systematic Review ◽  
High Speed ◽  
Total Bilirubin ◽  
Clinical Chemistry ◽  
Gamma Glutamyl Transferase ◽  
Pooled Data ◽  
Pubmed Search ◽  
Glutamyl Transferase ◽  
Study Designs ◽  
Clinical Chemistry Tests

Abstract Objectives Lipemia is the presence of abnormally high lipoprotein concentrations in serum or plasma samples that can interfere with laboratory testing. There is little guidance available from manufacturers or professional bodies on processing lipemic samples to produce clinically acceptable results. This systematic review summarizes existing literature on the effectiveness of lipid removal techniques in reducing interference in clinical chemistry tests. Methods A PubMed search using terms relating to lipid removal from human samples for clinical chemistry tests produced 1,558 studies published between January 2010 and July 2021. 15 articles met the criteria for further analyses. Results A total of 66 analytes were investigated amongst the 15 studies, which showed highly heterogenous study designs. High-speed centrifugation was consistently effective for 13 analytes: albumin, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, creatine kinase (CK), creatinine (Jaffe method), gamma-glutamyl transferase (GGT), glucose (hexokinase-based method), lactate dehydrogenase (LDH), phosphate, potassium, and urea. Lipid-clearing agents were uniformly effective for seven analytes: ALT, AST, total bilirubin, CK, creatinine (Jaffe method), lipase, and urea. Mixed results were reported for the remaining analytes. Conclusions For some analytes, high-speed centrifugation and/or lipid-clearing agents can be used in place of ultracentrifugation. Harmonized protocols and acceptability criteria are required to allow pooled data analysis and interpretation of different lipemic interference studies.

scholarly journals Early pregnancy reference intervals; 29 serum analytes from 4 to 12 weeks’ gestation in naturally conceived and uncomplicated pregnancies resulting in live births

2019 ◽  
Vol 57 (12) ◽  
pp. 1956-1967 ◽  
Author(s):  
Jesper Friis Petersen ◽  
Lennart J. Friis-Hansen ◽  
Andreas Kryger Jensen ◽  
Anders Nyboe Andersen ◽  
Ellen C.L. Løkkegaard
Keyword(s):  
Pregnant Women ◽  
Early Pregnancy ◽  
Clinical Chemistry ◽  
Clinical Care ◽  
Local Population ◽  
First Trimester ◽  
Reference Intervals ◽  
Specific Reference ◽  
Cancer Antigen 125 ◽  
Serum Samples

Abstract Background Pregnancy introduces major physiological changes that also alter biochemical analytes. Maternal and perinatal health can be optimized by early intervention and therefore, pregnancy-specific reference intervals (RIs) for the local population are warranted. While the second and third trimester-specific changes are well described, the first trimester is less well characterized. We therefore wanted to facilitate early detection of abnormalities by generating first trimester reference values for 29 common analytes. Methods In a prospective early pregnancy (PEP) cohort (2016–2017), 203 pregnant women were recruited from 4 to 8 weeks’ gestation. Consecutive blood samples were drawn every 2 weeks until an ongoing second trimester pregnancy (n = 164) or a miscarriage (n = 39) occurred. After exclusion of women with complicated pregnancies or deliveries (n = 42), 122 women were included. The serum samples collected at <6, 6–8, 8–10, 10–12 and >12 weeks’ gestation were analyzed for 29 common analytes. Subsequently the RIs were calculated according to the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommendations (2.5–97.5th percentiles) and compared with the conventional RIs for non-pregnant women. Results Human chorionic gonadotropin (hCG), progesterone (P4), estradiol (E2), pregnancy-associated plasma protein A (PAPP-A), cancer antigen 125 (CA125), thyroid stimulating hormone (TSH), creatinine (CREA) and albumin (ALB) showed an early pregnancy-dependent change compared with conventional limits. For ALB the change was seen at 5.5 weeks’ gestation. Conclusions We report gestational age-specific RIs available from the early part of the first trimester applicable to everyday clinical care of pregnant women. Well-known alterations of RIs seen in later trimesters are also observed in the first.

scholarly journals Measurement of Prostate-specific Antigen by Use of a Novel Blood Collection and Analytical System

2002 ◽  
Vol 48 (8) ◽  
pp. 1272-1278 ◽  
Author(s):  
Barbara R Grzeda ◽  
Tuan Le Bui ◽  
Cheryl N Warner ◽  
Tracy L Pirucki ◽  
Lisa M Dewey ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Whole Blood ◽  
Prostate Cancer Screening ◽  
Specific Antigen ◽  
Blood Collection ◽  
Serum Samples ◽  
Stabilizing Solution ◽  
Professional Assistance ◽  
Comparison Of The Results

Abstract Background: Prostate-specific antigen (PSA) is widely used in the detection and monitoring of prostate cancer. We developed a system for the self-collection and transport of capillary whole blood for PSA analysis, with the goal of reducing phlebotomy visits and, thus, increasing the access and utilization of PSA in prostate cancer screening and monitoring. Methods: The blood collection device [BIOSAFE Blood Transport System (BTSTM)] collects 70 μL of blood through a heparin-coated material into 200 μL of stabilizing solution. The diluted whole blood is used for measurement of PSA by a modified version of the Hybritech® Tandem-MP PSA Assay. Results were compared for matched samples of professionally and self-collected BTS blood and for matched BTS samples sera from blood collected by venipuncture. Imprecision for the whole-blood PSA measurement was estimated from analysis of whole-blood controls in duplicate, twice per day, over 20 days. Results: BTS samples (n = 140) collected by a qualified healthcare professional compared with serum samples yielded the regression equation: y =1.02x + 0.04 (Sy|x = 0.35; r = 0.99). Comparison of the results for samples (n = 128) collected by the patient without professional assistance with serum samples yielded: y = 1.08x + 0.02 (Sy|x = 0.31; r = 0.99). The between-run CVs at 0.069, 0.53, 2.9, and 10.7 μg/L were 21%, 6.0%, 3.5%, and 3.8%, respectively. PSA was stable in BTS samples stored for 21 days at 18–24 °C and for 7 days at 37 °C. Conclusion: The BIOSAFE BTS system allows accurate and convenient measurement of circulating PSA by a precise method for diluted whole blood.

scholarly journals Evaluation of the clinical chemistry tests analytical performance by using different models and specifications

2019 ◽  
Vol 45 (1) ◽  
pp. 11-18
Author(s):  
Murat Keleş
Keyword(s):  
Quality Management ◽  
Measurement Uncertainty ◽  
Goal Setting ◽  
Clinical Chemistry ◽  
Biological Variation ◽  
Analytical Performance ◽  
Analytical Quality ◽  
Analytical Error ◽  
Circular Letter ◽  
Clinical Chemistry Tests

Abstract Background The importance of managing analytical quality in clinical laboratories is known. Goal-setting models are critical for analytical quality management, along with correctly implemented error models. However, the methods used to determine analytical performance and more importantly, the relevant analytical quality goals are open to discussion. Our aim was to compare the analytical performance characteristics of routine clinical chemistry tests with different goal-setting models which was proposed by various establishments. In addition, to provide a perspective to Turkish total analytical error (TAE) circular letter that compulsory to calculate from 2016. Materials and methods This study was performed by the data obtained from the internal and external quality control of clinical chemistry tests which were measured by Roche Cobas c501 biochemistry analyzer. TAE calculated with TAE% = 1.65 ×(CV%) + Bias% formula. Nordtest uncertainty model was used in the calculation of measurement uncertainty (MU). In this context, total analytical error was evaluated with biological variation (BV), RCPA, CLIA and Turkish allowable total error (ATE) goals. Measurement uncertainty was evaluated with only permissible measurement uncertainty (pU%) goal. Results In our study, RCPA goals are the most stringent, followed by the BVEuBIVAS, BVRicos, pU%, CLIA and finally the ATETurkey goals coming in last. In cumulatively, BVEuBIVAS goals were 18.3% lower than BVRicos for evaluated parameters. Conclusion The balance between applicability and analytical assurance of goals should be well ensured when determining goal-setting models. Circular letter (2016/18) creates awareness to the analytical quality management but still open to development. Biological variation dependent total allowable error model never designed to be used as benchmarks for measurement uncertainty and it is not methodologically appropriate for assessing measurement uncertainty which was estimated by the Nordtest method. Also considered that, the use of “permissible MU” is more methodologically appropriate in the evaluation of measurement uncertainty.

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