Automated Measurement of Plasma Cell-Free Hemoglobin Using the Hemolysis Index Check Function

Abstract Background The Roche Cobas chemistry analyzer’s hemolysis index (HI) check function can directly report hemoglobin (Hb) concentrations. We aimed to validate the HI check function for the measurement of plasma cell-free Hb. Methods Plasma samples (6 μl) were taken by the analyzer and diluted in normal saline to measure the absorbance for Hb at 570 and 600 nm. Hb concentrations were calculated based on the molar extinction coefficient. Imprecision, lower limit of quantification (LLOQ), and analytical measurement range (AMR) of the assay were evaluated. The accuracy was determined by comparing the results between the new method and an existing spectrophotometric method. We further studied interference of icterus and lipemia and carryover. The performance of the assay in proficiency testing was also evaluated. The reference range was transferred from the existing method. Results Within-run and total CVs were 1.7%–4.2% and 2.1%–7.0%, respectively (n = 20). The LLOQ was 11 mg/dL (CV = 8.1%) with the upper limit of AMR of 506 mg/dL. The results of the new method correlated well with the existing reference assay: Y (new method) = 0.974 x (reference method) + 4.9, r = 0.9990, n = 52. Bilirubin with a concentration up to 60 mg/dL and lipemic index up to 389 did not show significant interference. No significant carryover was detected. The average standard deviation index in proficiency testing was 0.03 ± 0.29. The reference range was <22 mg/dL. Conclusions Plasma cell-free Hb measurement using the HI check function meets the analytical requirements of the plasma cell-free Hb assays. It is simple and cost-effective.

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Simple, cost-effective technique for portable digital eletrocorticography

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2000000300005 ◽

2000 ◽

Vol 58 (2B) ◽

pp. 424-427 ◽

Cited By ~ 1

Author(s):

PAULO R. M. DE BITTENCOURT ◽

MARCOS C. SANDMANN ◽

MARLUS S. MORO ◽

JOÃO C. DE ARAÚJO

Keyword(s):

Real Time ◽

Epilepsy Surgery ◽

Vascular Malformations ◽

Cost Effective ◽

New Method ◽

Cortical Lesions ◽

Effective Technique ◽

Seizure Disorders ◽

Operational Costs ◽

Cost Effective Technique

We revised 16 patients submitted to epilepsy surgery using a new method of digital, real-time, portable electrocorticography. Patients were operated upon over a period of 28 months. There were no complications. The exam was useful in 13 cases. The low installation and operational costs, the reliability and simplicity of the method, indicate it may be useful for defining the epileptogenic regions in a variety of circumnstances, including surgery for tumors, vascular malformations, and other cortical lesions associated with seizure disorders.

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Synchronous fluorescence as a green and selective tool for simultaneous determination of bambuterol and its main degradation product, terbutaline

Royal Society Open Science ◽

10.1098/rsos.181359 ◽

2018 ◽

Vol 5 (10) ◽

pp. 181359 ◽

Cited By ~ 4

Author(s):

Samah Abo El Abass ◽

Heba Elmansi

Keyword(s):

Degradation Product ◽

Low Cost ◽

Reference Method ◽

Cost Effective ◽

Zero Crossing ◽

Cost Effective Method ◽

Validation Parameters ◽

Main Degradation Product ◽

20 Nm

A green, sensitive and cost-effective method is introduced in this research for the determination of bambuterol and its main degradation product, terbutaline, simultaneously, relying on the synchronous spectrofluorimetric technique. First derivative synchronous spectrofluorimetric amplitude is measured at Δ λ = 20 nm, so bambuterol can be quantitated at 260 nm, and terbutaline can be measured at 290 nm, each at the zero crossing point of the other. The amplitude–concentration plots were linear over the concentration ranges of 0.2–6.0 µg ml −1 and 0.2–4.0 µg ml −1 for both bambuterol and terbutaline, respectively. Official guidelines were followed to calculate the validation parameters of the proposed method. The low values of limits of detection of 0.023, 0.056 µg ml −1 and limits of quantitation of 0.071, 0.169 µg ml −1 for bambuterol and terbutaline, respectively, point to the sensitivity of the method. Bambuterol is a prodrug for terbutaline, and the latter is considered its degradation product so the established method could be regarded as a stability-indicating one. Moreover, the proposed method was used for the analysis of bambuterol and terbutaline in their single ingredient preparations and the results revealed statistical agreement with the reference method. The suggested method, being a simple and low-cost procedure, is superior to the previously published methods which need more sophisticated techniques, longer analysis time and highly toxic solvents and reagents. It could be considered as an eco-friendly analytical procedure.

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The rapid determination of carcass fat by the Foss-Let specific gravity technique

British Journal Of Nutrition ◽

10.1079/bjn19760110 ◽

1976 ◽

Vol 36 (3) ◽

pp. 567-570 ◽

Cited By ~ 7

Author(s):

C. J. H. Woodward ◽

P. Trayhurn ◽

W. P. T. James

Keyword(s):

Specific Gravity ◽

Rapid Determination ◽

Reference Method ◽

New Method ◽

Storage Lipid ◽

Structural Lipid ◽

Nutritional Studies

1. Carcass fat was determined by extraction with tetrachloroethylene and measurement of the solvent's change in density. The results were comparable in precision to those of a reference method; the new method extracted storage lipid but little structural lipid.2. The technique is simple, rapid and appropriate for many nutritional studies.

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Detection of Breaking Waves in Single Wave Gauge Records of Surface Elevation Fluctuations

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-19-0011.1 ◽

2019 ◽

Vol 36 (9) ◽

pp. 1863-1879 ◽

Cited By ~ 1

Author(s):

Dan Liberzon ◽

Alexandru Vreme ◽

Sagi Knobler ◽

Itamar Bentwich

Keyword(s):

Water Waves ◽

Cost Effective ◽

Breaking Waves ◽

Recognition Algorithm ◽

New Method ◽

Surface Elevation ◽

Detection Accuracy ◽

Single Wave ◽

Accurate Detection ◽

Forced Waves

We report the development of a new method for accurate detection of breaking water waves that addresses the need for an accurate and cost-effective method that is independent of human decisions. The new detection method, which enables the detection of breakers using only surface elevation fluctuation measurements from a single wave gauge, supports the development of a new method for research relating to water waves and wind–wave interactions. According to the proposed method, detection is based on the use of the phase-time method to identify breaking-associated patterns in the instantaneous frequency variations of surface elevation fluctuations. A wavelet-based pattern recognition algorithm is devised to detect such patterns and provide accurate detection of breakers in the examined records. Validation and performance tests, conducted using both laboratory and open-sea data, including mechanically generated and wind-forced waves, are reported as well. These tests allow us to derive a set of parameters that assure high detection accuracy rates. The method is shown to be capable to achieve a positive detection rate exceeding 90%.

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Determination of Triglycidyl Isocyanurate in Workplace Air

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16224455 ◽

2019 ◽

Vol 16 (22) ◽

pp. 4455

Author(s):

Anna Jeżewska ◽

Joanna Kowalska

Keyword(s):

High Performance ◽

Limit Of Detection ◽

Crosslinking Agent ◽

Measurement Range ◽

Array Detector ◽

Phase System ◽

Limit Of Quantification ◽

Workplace Air ◽

Air Sample ◽

Triglycidyl Isocyanurate

Triglycidyl isocyanurate (TGIC) is a white solid in powder or granular form. TGIC does not occur naturally in the environment. It is intentionally manufactured and used as a crosslinking agent or hardener to produce polyester powder coatings. TGIC may cause genetic defects. This article presents the method of TGIC determination in workplace air using high-performance liquid chromatography (HPLC) with a diode-array detector (DAD). The method is based on the collection of TGIC present in the air on a polypropylene filter, extraction with acetonitrile, and chromatographic analysis of the solution obtained in this way. The determination was carried out in the reverse-phase system (mobile phase: acetonitrile: water) using an Ultra C18 column. The measurement range is 2 to 40 µg/m3 for a 720 liters air sample. Limit of detection (LOD) is 23 ng/m3 and limit of quantification (LOQ): 70 ng/m3. The method can be used for assessing occupational exposure to TGIC and associated risk to workers’ health.

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A Sensitive and Cost-Effective Chemiluminescence ELISA for Measurement of Amyloid-β 1-42 Peptide in Human Plasma

Journal of Alzheimer s Disease ◽

10.3233/jad-200861 ◽

2020 ◽

Vol 78 (3) ◽

pp. 1237-1244

Author(s):

Pankaj D. Mehta ◽

Bruce A. Patrick ◽

David L. Miller ◽

Patricia K. Coyle ◽

Thomas Wisniewski

Keyword(s):

Human Plasma ◽

Single Molecule ◽

Limit Of Detection ◽

Sandwich Elisa ◽

Amyloid Β ◽

Cost Effective ◽

Measurement Range ◽

Rabbit Monoclonal Antibody ◽

Low Levels ◽

The Brain

Background: Amyloid-β42 (Aβ42) is associated with plaque formation in the brain of patients with Alzheimer’s disease (AD). Studies have suggested the potential utility of plasma Aβ42 levels in the diagnosis, and in longitudinal study of AD pathology. Conventional ELISAs are used to measure Aβ42 levels in plasma but are not sensitive enough to quantitate low levels. Although ultrasensitive assays like single molecule array or immunoprecipitation-mass spectrometry have been developed to quantitate plasma Aβ42 levels, the high cost of instruments and reagents limit their use. Objective: We hypothesized that a sensitive and cost-effective chemiluminescence (CL) immunoassay could be developed to detect low Aβ42 levels in human plasma. Methods: We developed a sandwich ELISA using high affinity rabbit monoclonal antibody specific to Aβ42. The sensitivity of the assay was increased using CL substrate to quantitate low levels of Aβ42 in plasma. We examined the levels in plasma from 13 AD, 25 Down syndrome (DS), and 50 elderly controls. Results: The measurement range of the assay was 0.25 to 500 pg/ml. The limit of detection was 1 pg/ml. All AD, DS, and 45 of 50 control plasma showed measurable Aβ42 levels. Conclusion: This assay detects low levels of Aβ42 in plasma and does not need any expensive equipment or reagents. It offers a preferred alternative to ultrasensitive assays. Since the antibodies, peptide, and substrate are commercially available, the assay is well suited for academic or diagnostic laboratories, and has a potential for the diagnosis of AD or in clinical trials.

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Urea-Fibrinogen Slide Coagulase Test – A Simple Alternative Method for the Rapid Identification of Staphylococcus aureus

Journal of Gandaki Medical College-Nepal ◽

10.3126/jgmcn.v10i1.17903 ◽

2017 ◽

Vol 10 (1) ◽

pp. 5-10

Author(s):

Binita Koirala Sharma ◽

S Gokhale ◽

K Sharma

Keyword(s):

Staphylococcus Aureus ◽

Sensitivity And Specificity ◽

Reference Method ◽

Cost Effective ◽

Rapid Identification ◽

Accurate Identification ◽

Predictive Values ◽

Negative Results ◽

Animal Pathogens ◽

Sensitivity Specificity

Introduction: The accurate identification of Staphylococcus aureus clinical isolates requires a series of tests. Morphological features and slide coagulase test are two criteria on which S. aureus are identified. Resort to tube coagulase test is sought when results of slide coagulase test are equivocal or doubtful. Both coagulase tests detect the enzymes that convert fibrinogen into fibrin. Human, rabbit or sheep pooled plasma is used as substrate for both tests. Slide coagulase test is simpler and faster as compared to tube coagulase test. The plasma could be carrier of many human and animal pathogens like HIV, HBV, HCV etc. Storage of plasma for longer duration is fraught with chances of contamination. Improperly stored plasma can lead to false positive or negative results. Citrated plasma may be unsuitable for this test if contaminated with citrate utilizing bacteria. Considering the role of S. aureus as a common etiological agent in nosocomial and community infections, there is a need of implementing rapid, easy and cost-effective phenotypic test.Objectives: Considering the disadvantages and risks associated with fresh plasma, this study aims to launch for safer, more reliable substitute with longer shelf life that may provide reliable results for prompt identification of S. aureus by slide coagulase test.Methods: The present work evaluates slide coagulase test (SCT), and urea fibrinogen slide coagulase test (UF-SCT) for S. aureus detection considering Tube coagulase test (TCT) as the reference method. Sensitivity, specificity, positive predictive value and negative predictive values of SCT and UF-SCT were calculated using TCT as gold standard. Results: A total of 150 staphylococcal isolates from different clinical specimens ere selected for the evaluation of coagulase tests. All the specimens were subjected to SCT, UF-SCT and TCT. The UF-SCT showed better sensitivity (95.04%), specificity (100%), PPV (100%), and NPV (82.85%) with reference to TCT. UF-SCT showed similar sensitivity and specificity to SCT. None of the isolates were negative in UF-SCT and positive in SCT. Since UF-SCT does not incorporate plasma directly and at the same time has a very good sensitivity and specificity, it is recommended that UF-SCT could replace SCT for identification of S. aureus.Conclusion: The findings of present study shall encourage laboratories to use the urea-fibrinogen slide coagulase test routinely for the rapid identification of S aureus.Journal of Gandaki Medical College Vol. 10, No. 1, 2017, Page: 5-10

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Novel HILIC-ESI-MS method for urinary profiling of MSUD and methylmalonic aciduria biomarkers

Journal of Chromatographic Science ◽

10.1093/chromsci/bmz045 ◽

2019 ◽

Vol 57 (8) ◽

pp. 715-723

Author(s):

Elizabeth Mary Mathew ◽

Leslie Lewis ◽

Pragna Rao ◽

K Nalini ◽

Asha Kamath ◽

...

Keyword(s):

Formic Acid ◽

Malonic Acid ◽

Limit Of Detection ◽

Cost Effective ◽

Methylmalonic Aciduria ◽

Limit Of Quantification ◽

Maple Syrup ◽

Effective Manner ◽

Branched Chain ◽

Development And Validation

AbstractMethyl malonic acid and branched-chain keto acids are important biomarkers for the diagnosis of cobalamin deficiencies and maple syrup urine disease. We report the development and validation of a HILIC-ESI-MS2 method for the quantification of these organic acids from neonatal urine. The samples were 100 times diluted and analyzed on a ZIC-HILIC column with 25-mM formic acid in water: 25-mM formic acid in acetonitrile (45:55) at a flow rate of 0.8 mL/min with a runtime of only 6 minutes. The method demonstrated a lower limit of detection of 10 ng/mL, Limit of Quantification (LOQ) of 50 ng/mL, linearity of r2 ≥ 0.990 and recoveries of 87–105% for all analytes. The intraday and interday precision CV’s were <10% and 12%, respectively. Extensive stability studies demonstrated the analytes to be stable in stock and in matrix with a percent change within ±15%. The Bland–Altman analysis of the developed method with the gold standard GCMS method demonstrated a bias of 0.44, 0.11, 0.009 and –0.19 for methyl malonic acid, 3-methyl-2-oxovaleric acid, 2-hydroxy-3methylbutyric acid and 4-methyl-2-oxovaleric acid, respectively, proving the methods are comparable. The newly developed method involves no derivatization and has a simple sample preparation and a low runtime, enabling it to be easily automated with a high sample throughput in a cost-effective manner.

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Implementation and Validation of the Roche Light Cycler 480 96-Well Plate Platform as a Real-Time PCR Assay for the Quantitative Detection of Cytomegalovirus (CMV) in Clinical Specimens Using the Luminex MultiCode ASRs System

Medical Sciences ◽

10.3390/medsci8010014 ◽

2020 ◽

Vol 8 (1) ◽

pp. 14

Author(s):

Shengwen Calvin Li ◽

Kara J. Sparks ◽

Leonard S. Sender

Keyword(s):

Stem Cell ◽

Real Time ◽

Real Time Pcr ◽

Reference Range ◽

Measurement Range ◽

Quantitative Detection ◽

Clinical Settings ◽

Stem Cell Therapies ◽

Cell Therapies ◽

Copy Numbers

Allogenic stem-cell therapies benefit patients in the treatment of multiple diseases; however, the side effects of stem-cell therapies (SCT) derived from the concomitant use of immune suppression agents often include triggering infection diseases. Thus, analysis is required to improve the detection of pathogen infections in SCT. We develop a polymerase chain reaction (PCR)-based methodology for the qualitative real-time DNA detection of cytomegalovirus (CMV), with reference to herpes simplex virus types 1 (HSVI), Epstein–Barr virus (EBV), and varicella-zoster virus (VZV) in blood, urine, solid tissues, and cerebrospinal fluid. This real-time PCR of 96-well plate format provides a rapid framework as required by the Food and Drug Administration (FDA) for clinical settings, including the processing of specimens, reagent handling, special safety precautions, quality control criteria and analytical accuracy, precisely reportable range (analyst measurement range), reference range, limit of detection (LOD), analytical specificity established by interference study, and analyte stability. Specifically, we determined the reportable range (analyst measurement range) with the following criteria: CMV copies ≥200 copies/mL; report copy/mL value; CMV copies ≤199 copies/mL; report detected but below quantitative range; CMV copies = 0 with report <200 copies/mL. That is, with reference range, copy numbers (CN) per milliliter (mL) of the LOD were determined by standard curves that correlated Ct value and calibrated standard DNA panels. The three repeats determined that the measuring range was 1E2~1E6 copies/mL. The standard curves show the slopes were within the range −2.99 to −3.65 with R2 ≥ 0.98. High copy (HC) controls were within 0.17–0.18 log differences of DNA copy numbers; (2) low copy (LC) controls were within 0.17–0.18 log differences; (3) LOD was within 0.14–0.15 log differences. As such, we set up a fast, simple, inexpensive, sensitive, and reliable molecular approach for the qualitative detection of CMV pathogens. Conclusion: This real-time PCR of the 96-well plate format provides a rapid framework as required by the FDA for clinical settings.

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