1.Quality Improvement of Urinalysis Results Based on Automatic Sediment Urinalysis and Urine Strip Results.
A Jin LEE ; Cheon Gang PARK ; Young Chul BAE ; Chang Ho JEON
Journal of Laboratory Medicine and Quality Assurance 2017;39(4):154-161
BACKGROUND: Microscopic examinations are usually performed to confirm urine sediments in samples flagged in automated urinalysis. The aim of this study was to analyze the review rates and the difference in urinalysis results according to review rules. METHODS: A total of 1,408 urine samples submitted for health screening were collected. The urine chemistry test and urine sediment test were performed using EikenUS 3100 (Eiken Chemical Co. Ltd., Japan) and Sysmex UF-1000i (Sysmex Co., Japan), respectively. We assessed the rate of agreement between the 2 analyses and the kappa values for white blood cells (WBCs) and red blood cells (RBCs). Microscopic examinations were performed for all cases of discordant results between the urine strip and automated sediment analysis, some cases of concordant results, and cases of albuminuria. RESULTS: The review rate was 14.3%. Microscopic examinations were additionally performed on 77 samples (77/1,207, 6.4%) including 29 and 56 samples flagged for WBCs and RBCs, respectively. Based on the results of microscopic examination, the false-positive and the false-negative results of the urine chemistry test and automatic sediment analysis were corrected. Among concordant results between two methods, a clinically significant number of false-negatives were identified (6 results of WBC detection [6/125, 4.8%] and 4 of RBC detection [4/145, 2.8%]). Among the 22 unflagged cases of albuminuria, pathologic casts were detected in 21 cases (21/22, 95.5%). CONCLUSIONS: Microscopic examination based on the combined results of the two analyses improved the quality of the test.
Albuminuria
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Chemistry
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Erythrocytes
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Flow Cytometry
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Leukocytes
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Mass Screening
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Microscopy
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Quality Improvement*
;
Reagent Strips
;
Urinalysis*
2.Development of a lateral flow dipstick immunoassay for rapid detection of ginsenoside Re.
Tie-Gui NAN ; Zhen CAO ; Li-Shan HE ; Yuan YUAN ; Lu-Qi HUANG ; Bao-Min WANG
China Journal of Chinese Materia Medica 2013;38(16):2586-2589
A sensitive antibody-based lateral flow dipstick was developed for ginsenoside Re (GRe) detection. The stick consisted of a sample pad, a conjugate pad, membrane and an absorbent pad. The membrane was coated with two capture reagents, GRe-BSA conjugate and goat anti-mouse antibodies, forming a test line and a control line, respectively. The conjugate pad was saturated with colloidal gold particles coated with affinity purified monoclonal anti-GRe antibody. The visual detection limit was 200 microg x L(-1) of GRe and the reaction time was 10 min. The Panax ginseng roots were identified after these samples (10 mg) were extracted with 5 mL tap water for 30 min at room temperature, and the extracts were tested by the dipsticks and ELISA kit. The true and false P. ginseng could be distinguished with dipsticks. The dipstick could be used to detect the quality of the P. ginseng samples when the extract was diluted 100-folds. The results were compared with those obtained using an indirect competitive enzyme-linked immunosorbent assay (icELISA). The dipstick assay proved to be a sensitive and rapid tool for quality control of P. ginseng.
Animals
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Antibodies, Monoclonal
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immunology
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Counterfeit Drugs
;
analysis
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Ginsenosides
;
analysis
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Immunoassay
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instrumentation
;
methods
;
Mice
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Panax
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chemistry
;
Reagent Strips
;
Time Factors
3.Colloidal gold immunochromatographic strip for rapid detection of melamine.
Yunfei GONG ; Zonglun CHEN ; Xi XI ; Mujie LI ; Weifen WANG ; Minzi WANG ; Yongfei YING ; Mingzhou ZHANG
Chinese Journal of Biotechnology 2012;28(7):887-898
To develop a specific, rapid, and convenient immunochromatography assay (ICA) to detect melamine residues in dairy products and feed sample. Colloidal gold particles labeled with purified monoclonal antibody against anti-melamine were used as the detector reagent. The MEL-OVA (the conjugate of melamine and ovalbumin) and goat anti-mouse melamine IgG were blotted on the test and control regions of nitrocellulose membrane. The strip was then assembled with sample pad, absorbing pad, and dorsal shield. The limit of detection (LOD) is 50 microg/L. The test trip was applied to detect melamine in milk, milk powder, and animal feeds, with detection limits of 100 microg/L for milk, 100 ng/g for milk powder, 200 ng/g for feeds. Compared to LC-MS/MS, the ICA could be used to screen a large number of dairy products and feed samples for melamine residue.
Animals
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Antibodies, Monoclonal
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chemistry
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Cattle
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Dairy Products
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analysis
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Food Contamination
;
analysis
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Gold Colloid
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chemistry
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Immunochromatography
;
methods
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Milk
;
chemistry
;
Reagent Strips
;
chemical synthesis
;
chemistry
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Sensitivity and Specificity
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Triazines
;
analysis
4.Novel ractopamine-protein carrier conjugation and its application to the lateral flow strip test for ractopamine detection in animal feed.
Pattarachaya PREECHAKASEDKIT ; Nattaya NGAMROJANAVANICH ; Nanthika KHONGCHAREONPORN ; Orawon CHAILAPAKUL
Journal of Zhejiang University. Science. B 2019;20(2):193-204
In this work, a novel conjugate of ractopamine and bovine serum albumin (RAC-BSA) has been developed via the Mannich reaction, with a mole coupling ratio for RAC-BSA of 9:1. The proposed conjugation method provides a simple and one-step method with the use of fewer reagents compared with other conjugation methods for competitive immunoassays. RAC-BSA conjugation was used to fabricate a competitive lateral flow strip test for RAC detection in animal feed. For sample preparation, RAC was spiked in swine feed purchased from the local markets in Thailand, and methanol and running buffer at a volume ratio of 10:90 was used as extraction buffer. The procedures for sample preparation were completed within 25 min. Under optimal conditions, the limit of detection (LOD), assessed by the naked eye within 5 min, was found to be 1 ng/g. A semi-quantitative analysis was also conducted using a smart phone and computer software, with a linearity of 0.075-0.750 ng/g, calculated LOD of 0.10 ng/g, calculated limit of quantitation of 0.33 ng/g, and good correlation of 0.992. The recoveries were found in the range of 96.4%-103.7% with a relative standard deviation of 2.5%-3.6% for intra- and inter-assays. Comparison of the results obtained by the strip test with those obtained by enzyme-linked immunosorbent assay had a good agreement in terms of accuracy. Furthermore, this strip test exhibited highly specific RAC detection without cross reactivity with related compounds. Therefore, the RAC-BSA conjugation via the Mannich reaction can be accepted as a one-step and easy conjugation method and applied to the competitive lateral flow strip test.
Animal Feed/analysis*
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Animals
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Cross Reactions
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Enzyme-Linked Immunosorbent Assay/methods*
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Limit of Detection
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Phenethylamines/chemistry*
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Reagent Strips
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Serum Albumin, Bovine/chemistry*
;
Swine
5.Comparison of Urine Albumin-to-Creatinine Ratio (ACR) Between ACR Strip Test and Quantitative Test in Prediabetes and Diabetes.
Eun Hee NAH ; Seon CHO ; Suyoung KIM ; Han Ik CHO
Annals of Laboratory Medicine 2017;37(1):28-33
BACKGROUND: Albuminuria is generally known as a sensitive marker of renal and cardiovascular dysfunction. It can be used to help predict the occurrence of nephropathy and cardiovascular disorders in diabetes. Individuals with prediabetes have a tendency to develop macrovascular and microvascular pathology, resulting in an increased risk of retinopathy, cardiovascular diseases, and chronic renal diseases. We evaluated the clinical value of a strip test for measuring the urinary albumin-to-creatinine ratio (ACR) in prediabetes and diabetes. METHODS: Spot urine samples were obtained from 226 prediabetic and 275 diabetic subjects during regular health checkups. Urinary ACR was measured by using strip and laboratory quantitative tests. RESULTS: The positive rates of albuminuria measured by using the ACR strip test were 15.5% (microalbuminuria, 14.6%; macroalbuminuria, 0.9%) and 30.5% (microalbuminuria, 25.1%; macroalbuminuria, 5.5%) in prediabetes and diabetes, respectively. In the prediabetic population, the sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of the ACR strip method were 92.0%, 94.0%, 65.7%, 99.0%, and 93.8%, respectively; the corresponding values in the diabetic population were 80.0%, 91.6%, 81.0%, 91.1%, and 88.0%, respectively. The median [interquartile range] ACR values in the strip tests for measurement ranges of <30, 30-300, and >300 mg/g were 9.4 [6.3-15.4], 46.9 [26.5-87.7], and 368.8 [296.2-575.2] mg/g, respectively, using the laboratory method. CONCLUSIONS: The ACR strip test showed high sensitivity, specificity, and negative predictive value, suggesting that the test can be used to screen for albuminuria in cases of prediabetes and diabetes.
Adult
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Aged
;
Aged, 80 and over
;
Albumins/*analysis
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Creatinine/*urine
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Diabetes Mellitus, Type 2/pathology/urine
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Female
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Humans
;
*Immunoassay
;
Male
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Middle Aged
;
Prediabetic State/pathology/urine
;
Reagent Strips/chemistry
6.Usefulness of Reagent Strips for the Diagnosis of Spontaneous Bacterial Peritonitis.
Dae Kyoum KIM ; Dong Jin SUH ; Gi Deog KIM ; Won Beom CHOI ; Sung Hoon KIM ; Young Suk LIM ; Han Chu LEE ; Yong Hwa CHUNG ; Yung Sang LEE
The Korean Journal of Hepatology 2005;11(3):243-249
BACKGROUND/AIMS: Spontaneous bacterial peritonitis (SBP) is one of the potentially life-threatening complications for patients with liver cirrhosis, and it has a mortality rate of over 20%. Early diagnosis of SBP and immediate use of an adequate antibiotic therapy are very important for achieving a better prognosis. The aim of our study was to assess the usefulness of reagent strips for making the rapid diagnosis of SBP. METHODS: A diagnostic paracentesis procedure was performed upon hospital admission in 257 cirrhotic patients (187 males, 70 females; mean age: 54 years) with ascites. Each fresh sample of ascitic fluid was tested using a reagent strip, and the result was scored as 0, 1+, 2+ or 3+. The leukocyte count, polymorphonuclear cell count, blood bottle culture, and chemistry of ascites were also done. RESULTS: We diagnosed 79 cases of SBP and 2 cases of secondary bacterial peritonitis by means of the polymorphonuclear cell count and the classical criteria. When a reagent strip result of 3+ was considered positive, the test's sensitivity was 86% (70 of 81), the specificity was 100% (176 of 176), and the positive predictive value was 94%. Furthermore, when a reagent strip result of 2+ or more was considered positive, the test sensitivity was 100% (81 of 81), the specificity was 99% (174 of 176), and negative predictive value was 99%. CONCLUSIONS: The use of reagent strips is a very sensitive and specific tool for the rapid diagnosis of SBP in cirrhotic patients. A positive result should be an indication for empirical antibiotic therapy, and a negative result may be useful as a screening test to exclude SBP.
Aged
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Ascitic Fluid/chemistry/cytology
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Bacterial Infections/*diagnosis/microbiology
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English Abstract
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Female
;
Humans
;
Liver Cirrhosis/complications
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Male
;
Middle Aged
;
Peritonitis/*diagnosis/etiology/microbiology
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Predictive Value of Tests
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*Reagent Strips
;
Sensitivity and Specificity
7.Research of on-line vision inspection technology for width of NC membrane.
Yao TANG ; Shu HU ; Xi CHEN ; Fanfan LI
Journal of Biomedical Engineering 2012;29(4):669-672
This paper presents a vision-based method for the width of NC membrane online inspection. In the production of bio-test strip, the number of antigen or antibody which is coated on the membrane depends on the width and the uniformity of test line T and control line C. People should control the width and the uniformity strictly to ensure the accuracy of lines in order to achieve quantitative inspection with high sensitivity. And online inspection must be done, it cannot be processed when the solution has been dry up. This paper gives a design of online inspection system based on linear charge-coupled device (linear CCD), it makes such advantages in terms of speed, accuracy, and the operation to achieve real-time, online inspection.
Biosensing Techniques
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instrumentation
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Diagnostic Techniques, Ophthalmological
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Enzyme-Linked Immunosorbent Assay
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Gold Colloid
;
chemistry
;
Humans
;
Immunosorbent Techniques
;
instrumentation
;
Online Systems
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Photometry
;
instrumentation
;
Reagent Strips
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Vision Tests
;
instrumentation
;
methods
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Vision, Ocular
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Visual Acuity