Centralization of multisite reagent lot-to-lot validation for Ortho Clinical Vitros chemistry instruments.

OBJECTIVE: Reagent lot-to-lot comparisons are recommended by accreditation bodies to ensure that the performance of each reagent lot meets acceptable standards for quality patient results. The general approach is comprised of performing quality control (QC) and patient comparison between the old and new reagent lots and evaluating against a pre-defined criteria. Reagent lot comparison practices are often variable despite using the same instrument across different laboratories. This is costly, time consuming, and can lead to variability in acceptance criteria. While Clinical & Laboratory Standards Institute (CLSI) has a recommended guideline for reagent lot validation, it is often difficult to execute for small and rural laboratories due to limited resources. Defining the analytes required for detailed validation is important to allocate appropriate resources to ensure quality patient results. The goal of this study was to develop a standardized approach to reagent lot validation and optimize lab resources on Vitros chemistry instruments. DESIGN AND METHOD: This study consists of a retrospective and prospective analysis of reagent lot changes in dry slide chemistry analyzers (Ortho Clinical Diagnostics Vitros). Two years of retrospective reagent lot comparison data was obtained at a single site. A prospective study was conducted by assessing aliquots of 10 patient sample pools at 9 sites with Vitros analyzers. RESULTS: Of the 19 chemistry analytes evaluated, albumin, sodium, and total protein showed significant differences between reagent lots and also exceeded the pre-defined acceptance criteria. CONCLUSION: For these analytes, our recommendations are to perform a comprehensive lot validation with QC and patient samples. A simple lot validation with a reflex approach comprised of initially assaying QC can be adapted for the more stable analytes to allow achieving quality patient result in a resource constraint rural environment.

Evaluation of the quick-clotting serum separator tube, VQ-Tube™, for clinical chemistry and thyroid hormone assays.

BACKGROUND: The type of blood collection tube affects specimen quality and laboratory results. Because plasma specimens have a shorter processing time compared with serum specimens, emergency biochemistry tests use plasma. However, serum specimens remain stable after centrifugation and show more accurate results than plasma. Therefore, a quick-clotting serum separator tube is expected to be useful for shorter turnaround times and accurate results. We evaluated a new quick-clotting serum separator tube VQ-Tube™ (AB Medical, Korea) for clinical chemistry and thyroid hormone assays. METHODS: One hundred volunteers from four university hospitals were recruited, and peripheral blood samples were collected in quick-clotting serum separator tube VQ-Tubes™ and the commonly used serum separator tube V-Tubes™. The obtained specimens were used for 16 clinical chemistry assays and three thyroid hormone assays. RESULTS: The differences (%) in the test results obtained from the samples in each tube satisfied the allowable difference ranges (19 assays). The differences in the test results between the tubes satisfied the desired specifications for accuracy except for the glucose results (2.75%). The paired t-test revealed significant differences between the results of six assays, but each set of results showed a good correlation. Samples were visually inspected for serum clarity and gel barrier integrity, and incomplete clotting reactions and haemolysed serum were not observed. CONCLUSIONS: The new quick-clotting VQ-Tube™ demonstrated reliable test results compared with the commonly used serum separator tube V-Tube™. This quick-clotting tube will provide fast test results with adequately separated serum specimens, especially for patients who need fast tests.

Performance characteristics of automated clinical chemistry analyzers using commercial assay reagents contributing to quality assurance and clinical decision in a hospital laboratory.

Background: Clinical laboratories provide essential diagnostic services that are essential in clinical decision making, contributing to the quality of healthcare. The performance of two Siemens ADVIA 1800 analyzers was characterized in a hospital Biochemistry laboratory in order to evaluate the analytical characteristics of such automated analyzer systems using nonoriginal assay reagents attempting to support laboratory quality service and crucial clinical decision making. Methods: We independently completed performance validation studies including trueness, precision, sensitivity as well as measurement of uncertainty and sigma metrics calculation for 25 biochemical parameters. Results: Trueness expressed as bias was less than 20% for both ADVIA 1800 analyzers. Within run and total precisions expressed as CV% were ≤9.85% on both analyzers for most parameters studied with few exceptions (Mg, TB, DB, Cl, HDL and UA) observed either in low or in high level samples and between the two analyzers. LoB, LoD and LoQ values produced by the two analyzers were comparable except Cl. Uncertainty values produced by the two analyzers were comparable with no significant differences. Quality performance of reagent assays was studied using the sigma metrics system. The sigma values were plotted on normalized method decision charts for graphical representation of assay performances for each analyzer. Conclusions: The two ADVIA systems, independently evaluated, showed consistent performance characteristics with certain discrepancies by several reagents. Sigma analysis was helpful for revealing the quality performance of non-original reagents supporting the need for strict assessment of quality assurance and in some instances optimization/improvement of assay methods.

Age-specific and sex-specific reference intervals for non-fasting lipids and apolipoproteins in 7260 healthy Chinese children and adolescents measured with an Olympus AU5400 analyser: a cross-sectional study.

AIMS: Ethnic, demographic, lifestyle, genetic and environmental factors influence lipids and apolipoproteins. The aim of this study was to establish age-specific and gender-specific reference intervals for non-fasting lipids and apolipoproteins in healthy Chinese children and adolescents. METHODS: This study followed the Clinical and Laboratory Standards Institute EP28-A3c guidelines. Non-fasting samples were collected from 7260 healthy Chinese children and adolescents, and they were analysed using the Olympus AU5400 analyser for: triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 and apolipoprotein B (ApoB). The age-related and gender-related reference intervals were partitioned using the Harris-Boyd method. The non-parametric method was used to establish the lower limit (2.5th percentile) and the upper limit (97.5th percentile) for the reference intervals. The 90% CIs for the lower and upper limits were also calculated. RESULTS: Based on the Harris-Boyd method, gender partitions were required for TC, LDL-C and ApoB. Age differences were observed for all analytes. Paediatric reference intervals were established for non-fasting lipids and apolipoproteins based on a large population of healthy children and adolescents. CONCLUSIONS: Previously used reference intervals did not take age and gender into account. These age-specific and gender-specific reference intervals established in this study may contribute to improved management and assessment of paediatric diseases.

Performance Evaluation of an Enzyme-Linked Immunosorbent Assay for Seven Autoantibodies in Lung Cancer.

BACKGROUND: To verify and evaluate the performance characteristics of an enzyme-linked immunosorbent assay (ELISA) assay kit (Hangzhou Cancer probe Biotech Company) for seven autoantibodies (7-AABS), including p53, GAGE7, PGP9.5, CAGE, MAGEA1, SOX2, and GBU4-5. METHODS: Evaluation was carried out according to "Guidelines for performance evaluation of in vitro diagnostic reagent". The performance parameters included detection limit, reportable range, precision, accuracy, and method comparison. RESULTS: The detection limit was less than 3.75 U/mL. Reportable range was from 3.75 U/mL to 60 U/mL. The coefficient of variations (CVs) of within-run of 7-AABS were 5.15% - 10.13%, and between-run of CVs were 3.41% - 8.80%. For accuracy verification, the relative deviations (Bias) were all lower than 15% in the indicated concentration range. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and ac-curacy were 35.9%, 90.0%, 80.3%, 55.3%, 61.3%, respectively. CONCLUSIONS: Overall, the verification study demonstrated the performance of the kit meets the testing requirements. It is qualified for clinical applications.

Performance Evaluation of the Mindray BC 6800 Hematology Analyzer and Flag Comparison with the XE-2100 and Manual Microscopy.

BACKGROUND: The Mindray BC-6800 automated hematology analyzer is an automated hematology analyzer and 5-part leukocyte differential counter for in vitro diagnostic use in clinical laboratories. It is necessary to undergo an evaluation before the instrument is used to test patient samples. METHODS: The performance was evaluated with regards to precision, linearity, carry-over, and method comparison. The flag performances were evaluated and compared with the Sysmex XE-2100 hematology analyzer and manual microscope in the hematology laboratory of a tertiary hospital in China. RESULTS: There was minimal carryover (< 0.05%) and excellent linearity for white blood cells and platelet (PLT) counts (r > 0.999). The BC-6800 displayed very good correlation (r > 0.97) with the XE-2100 for blood cell count and cell differential parameters. In a comparison of 295 leukocyte differential count results analyzed in parallel with manual microscopy, the main flags (immature granulocytes, blasts, abnormal lymphocytes) showed approxi-mately the same sensitivity and specificity on both analyzers (sensitivity > 90%, specificity > 78%). CONCLUSIONS: The BC-6800 showed excellent performance and supplied confidence in flag information for abnormal samples in the routine hematology laboratory.

A simplified and miniaturized glucometer-based assay for the detection of ß-glucosidase activity.

ß-Glucosidase activity assays constitute an important indicator for the early diagnosis of neonatal necrotizing enterocolitis and qualitative changes in medicinal plants. The drawbacks of the existing methods are high consumption of both time and reagents, complexity in operation, and requirement of expensive instruments and highly trained personnel. The present study provides a simplified, highly selective, and miniaturized glucometer-based strategy for the detection of ß-glucosidase activity. Single-factor experiments showed that optimum ß-glucosidase activity was exhibited at 50 °C and pH 5.0 in a citric acid-sodium citrate buffer when reacting with 0.03 g/mL salicin for 30 min. The procedure for detection was simplified without the need of a chromogenic reaction. Validation of the analytical method demonstrated that the accuracy, precision, repeatability, stability, and durability were good. The linear ranges of ß-glucosidase in a buffer solution and rat serum were 0.0873-1.5498 U/mL and 0.4076-2.9019 U/mL, respectively. The proposed method was free from interference from ß-dextranase, snailase, ß-galactosidase, hemicellulase, and glucuronic acid released by baicalin. This demonstrated that the proposed assay had a higher selectivity than the conventional dinitrosalicylic acid (DNS) assay because of the specificity for salicin and unique recognition of glucose by a personal glucose meter. Miniaturization of the method resulted in a microassay for ß-glucosidase activity. The easy-to-operate method was successfully used to detect a series of ß-glucosidases extracted from bitter almonds and cultured by Aspergillus niger. In addition, the simplified and miniaturized glucometer-based assay has potential application in the point-of-care testing of ß-glucosidase in many fields, including medical diagnostics, food safety, and environmental monitoring.

Performance and Suitability of Mindray BS480©: A Fully Open Clinical Chemistry Analyzer.

BACKGROUND: Mindray BS480©, a multi-parametric and random-access clinical chemistry instrument, is suitable for medium-sized hospital applications. Large laboratories in hospital environments require high throughput non-emergency settings that could slow routine production lines. In addition, the possibility to adapt to different methodologies is of great convenience for improving the transfer from manual to automated applications. The aim of the study is to evaluate analytical performances and to draw a comparison between analyzers for most common clinical parameters under simulated routine conditions. METHOD: Analytical performances in term of imprecision and comparison studies were performed between Mindray BS480© and reference analyzers such as Cobas 8000© for 12 routine parameters and ABX Pentra 400© for pyruvate and acetoacetate. Mindray BS480© usability, in terms of throughput and emergency sample handling, was also evaluated. RESULTS: Imprecision CVs for different analytes ranged from 0.7% to 7.9%, and the comparison study regression slope ranged from 0.74 to 1.22. Mindray workflow and emergency modes covered automated specifications. CONCLUSION: Results are considered significant for colorimetric, turbidimetric and ISE assays. Most performances were in line with Mindray and current recommendations. Mindray BS480© provides precise measurements for a variety of analytes. The possibility to adapt some methodologies is very useful, leading to a switch from manual methodology to automation.

Influence of centrifugation conditions on the results of 77 routine clinical chemistry analytes using standard vacuum blood collection tubes and the new BD-Barricor tubes.

INTRODUCTION: Although centrifugation is performed in almost every blood sample, recommendations on duration and g-force are heterogeneous and mostly based on expert opinions. In order to unify this step in a fully automated laboratory, we aimed to evaluate different centrifugation settings and their influence on the results of routine clinical chemistry analytes. MATERIALS AND METHODS: We collected blood from 41 healthy volunteers into BD Vacutainer PST II-heparin-gel- (LiHepGel), BD Vacutainer SST II-serum-, and BD Vacutainer Barricor heparin-tubes with a mechanical separator (LiHepBar). Tubes were centrifuged at 2000xg for 10 minutes and 3000xg for 7 and 5 minutes, respectively. Subsequently 60 and 21 clinical chemistry analytes were measured in plasma and serum samples, respectively, using a Roche COBAS instrument. RESULTS: High sensitive Troponin T, pregnancy-associated plasma protein A, ß human chorionic gonadotropin and rheumatoid factor had to be excluded from statistical evaluation as many of the respective results were below the measuring range. Except of free haemoglobin (fHb) measurements, no analyte result was altered by the use of shorter centrifugation times at higher g-forces. Comparing LiHepBar to LiHepGel tubes at different centrifugation setting, we found higher lactate-dehydrogenase (LD) (P = 0.003 to < 0.001) and lower bicarbonate values (P = 0.049 to 0.008) in the latter. CONCLUSIONS: Serum and heparin samples may be centrifuged at higher speed (3000xg) for a shorter amount of time (5 minutes) without alteration of the analytes tested in this study. When using LiHepBar tubes for blood collection, a separate LD reference value might be needed.

Medical Devices; Clinical Chemistry and Clinical Toxicology Devices; Classification of the Organophosphate Test System. Final order.

The Food and Drug Administration (FDA or we) is classifying the organophosphate test system into class II (special controls). The special controls that apply to the device type are identified in this order and will be part of the codified language for the organophosphate test system's classification. We are taking this action because we have determined that classifying the device into class II (special controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.

Do Serum Creatinine Levels Show Clinically Significant Fluctuations on Serial Determinations on the Siemens Advia 1800 Analyzer?

BACKGROUND: The goal of this work was to determine whether there are clinically significant fluctuations in the level of serum creatinine on serial determinations, especially in the borderline range (1.1-1.3 mg/dl), after specimen storage. METHODS: Sixty-one serum samples were analyzed. They were divided into three categories based on the initial serum creatinine measurement: low (≤1.0 mg/dl), borderline (1.1-1.3 mg/dl), and high (≥1.4 mg/dl). The specimens were stored at 4°C and run on the Siemens Advia 1800 chemistry analyzer on days 1, 3, and 11. RESULTS: Statistical comparisons of the three groups were made using the unpaired t-test, yielding a two-tailed P-value for each group comparison. The P-values ranged from 0.0829 to 0.3892, indicating no statistically significant difference between the standard deviations of each group. CONCLUSIONS: Mild-to-moderate fluctuations in precision occur in successive serum creatinine determinations. The overwhelming majority of these fluctuations should not affect clinical decision making.

An integrated platform for directly widely-targeted quantitative analysis of feces part II: An application for steroids, eicosanoids, and porphyrins profiling.

Steroids, especially bile acids, along with eicosanoids and porphyrins in feces play pivotal roles for the clinical diagnosis of various diseases. However, their reliable measurement is extensively obstructed by poor stability, structural diversity, broad content ranges, and tedious sample preparation protocols that account for a majority of the measurement errors. In current study, in-depth component screening was initially carried out by flexibly integrating diverse modes, such as predefined multiple reaction monitoring, stepped multiple ion monitoring, neutral loss scan, and precursor ion scan on a hybrid triple quadrupole-linear ion trap mass spectrometer, which also provided MS(2) spectra via enhanced product ion experiments. Meanwhile, a hybrid ion trap-time of flight mass spectrometer served as a complementary tool by providing accurate mass spectral information. Afterwards, because authentic compounds were unavailable for most analytes, an online optimization strategy was then proposed to optimize parameters, including precursor-to-product ion transitions and spectrometric parameters, notably collision energy. Finally, direct analysis of all detected components in feces was carried out by employing a platform integrating online pressurized liquid extraction, turbulent flow chromatography, and LC-MS/MS, and applying those optimized parameters. Seventy-one compounds, including 52 steroids and 13 eicosanoids, together with 6 porphyrins, were found and annotated in a fecal pool, and then relatively quantified in various fecal matrices. The quantitative dataset was subjected for multivariate statistical analysis and significant differences were observed among the quantitative chemome profiles of the fecal matrices from different groups. The findings obtained in the two parts demonstrated that the analytical platform in combination with the work-flow is qualified for not only directly simultaneous measurement of diverse endogenous substances, but widely targeted metabolomics of fecal matrices.

Oscillatory multiphase flow strategy for chemistry and biology.

Continuous multiphase flow strategies are commonly employed for high-throughput parameter screening of physical, chemical, and biological processes as well as continuous preparation of a wide range of fine chemicals and micro/nano particles with processing times up to 10 min. The inter-dependency of mixing and residence times, and their direct correlation with reactor length have limited the adaptation of multiphase flow strategies for studies of processes with relatively long processing times (0.5-24 h). In this frontier article, we describe an oscillatory multiphase flow strategy to decouple mixing and residence times and enable investigation of longer timescale experiments than typically feasible with conventional continuous multiphase flow approaches. We review current oscillatory multiphase flow technologies, provide an overview of the advancements of this relatively new strategy in chemistry and biology, and close with a perspective on future opportunities.

Transference of CALIPER pediatric reference intervals to biochemical assays on the Roche cobas 6000 and the Roche Modular P.

OBJECTIVES: The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) has recently established pediatric age- and sex-specific reference intervals for over 85 biochemical markers on the Abbott Architect system. Previously, CALIPER reference intervals for several biochemical markers were successfully transferred from Abbott assays to Roche, Beckman, Ortho, and Siemens assays. This study further broadens the CALIPER database by performing transference and verification for 52 biochemical assays on the Roche cobas 6000 and the Roche Modular P. DESIGN AND METHODS: Using CLSI C28-A3 and EP9-A2 guidelines, transference of the CALIPER reference intervals was attempted for 16 assays on the Roche cobas 6000 and 36 on the Modular P. Calculated reference intervals were further verified using 100 healthy CALIPER samples. RESULTS: Most assays showed strong correlation between assay systems and were transferable from Abbott to the Roche cobas 6000 (81%) and the Modular P (86%). Bicarbonate and magnesium were not transferable on either system and calcium and prealbumin were not transferable to the Modular P. Of the transferable analytes, 62% and 61% were verified on the cobas 6000 and the Modular P, respectively. CONCLUSIONS: This study extends the utility of the CALIPER database to two additional analytical systems, which facilitates the broad application of CALIPER reference intervals at pediatric centers utilizing Roche biochemical assays. Transference studies across different analytical platforms can later be collectively analyzed in an attempt to develop common reference intervals across all clinical chemistry instruments to harmonize laboratory test interpretation in diagnosis and monitoring of pediatric disease.

Clinical chemistry measurements with commercially available test slides on a smartphone platform: Colorimetric determination of glucose and urea.

BACKGKROUND: Rapidly increasing healthcare costs in economically advantaged countries are currently unsustainable, while in many developing nations, even 50-year-old technologies are too expensive to implement. New and unconventional technologies are being explored as solutions to this problem. In this study, we examined the use of a smartphone as the detection platform for 2 well-developed, relatively inexpensive, commercially available clinical chemistry assays as a model for rapid and inexpensive clinical diagnostic testing. METHODS: An Apple iPhone 4 camera phone equipped with a color analysis application (ColorAssist) was combined with Vitros® glucose and urea colorimetric assays. Color images of assay slides at various concentrations of glucose or urea were collected with the iPhone 4 and quantitated in three different spectral ranges (red/green/blue or RGB) using the ColorAssist app. When the diffuse reflectance data was converted into absorbance, it was possible to quantitate glucose or blood urea nitrogen (BUN) over their clinically important concentration ranges (30-515mg/dl for glucose or 2-190mg/dl for BUN), with good linearity (R(2)=0.9994 or 0.9996, respectively [n=5]). RESULTS: Data collected using the iPhone 4 and canine serum samples were in agreement with results from the instrumental "gold standard" (Beckman Coulter AU480 Chemistry System) (R(2)=0.9966 and slope=1.0001 for glucose; R(2)=0.9958 and slope=0.9454 for BUN). Glucose determinations of serum samples made using this smartphone method were as accurate as or more accurate than a commercial colorimetric dry slide analyzer (Heska® Element DC Chemistry Analyzer, Loveland, CO) and 2 glucometers: ReliOn® Ultima (Abbott Diabetes Care Inc) and Presto® (AgaMatrix Inc.H). BUN determinations made using the smartphone approach were comparable in accuracy to the Heska instrument. CONCLUSION: This demonstration shows that smartphones have the potential to be used as simple, effective colorimetric detectors for quantitative diagnostic tests, and may be applicable for both point-of-care applications in the developed world and field deployment in developing nations.

Multi-center evaluation of analytical performance of the Beckman Coulter AU5822 chemistry analyzer.

OBJECTIVES: Our three academic institutions, Indiana University, Northwestern Memorial Hospital, and Wake Forest, were among the first in the United States to implement the Beckman Coulter AU5822 series chemistry analyzers. We undertook this post-hoc multi-center study by merging our data to determine performance characteristics and the impact of methodology changes on analyte measurement. DESIGN AND METHODS: We independently completed performance validation studies including precision, linearity/analytical measurement range, method comparison, and reference range verification. Complete data sets were available from at least one institution for 66 analytes with the following groups: 51 from all three institutions, and 15 from 1 or 2 institutions for a total sample size of 12,064. RESULTS: Precision was similar among institutions. Coefficients of variation (CV) were <10% for 97%. Analytes with CVs >10% included direct bilirubin and digoxin. All analytes exhibited linearity over the analytical measurement range. Method comparison data showed slopes between 0.900-1.100 for 87.9% of the analytes. Slopes for amylase, tobramycin and urine amylase were <0.8; the slope for lipase was >1.5, due to known methodology or standardization differences. Consequently, reference ranges of amylase, urine amylase and lipase required only minor or no modification. CONCLUSION: The four AU5822 analyzers independently evaluated at three sites showed consistent precision, linearity, and correlation results. Since installations, the test results had been well received by clinicians from all three institutions.