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  1. Lai MY, Ooi CH, Lau YL
    Am. J. Trop. Med. Hyg., 2018 03;98(3):700-703.
    PMID: 29260656 DOI: 10.4269/ajtmh.17-0738
    The aim of this study was to develop a recombinase polymerase amplification (RPA) combined with a lateral flow (LF) strip method for specific diagnosis of Plasmodium knowlesi. With incubation at 37°C, the 18S rRNA gene of P. knowlesi was successfully amplified within 12 minutes. By adding a specifically designed probe to the reaction solution, the amplified RPA product can be visualized on a LF strip. The RPA assay exhibited high sensitivity with limits of detection down to 10 parasites/μL of P. knowlesi. Nonetheless, it was demonstrated that all P. knowlesi (N = 41) and other Plasmodium sp. (N = 25) were positive while negative samples (N = 8) were negative. Therefore, a combination of RPA and LF strip detection is a highly promising approach with the potential to be suitable for use in resource-limited settings.
    Matched MeSH terms: Reagent Strips*
  2. Yusof NA, Kadir WA
    PMID: 19010723 DOI: 10.1016/j.saa.2008.07.019
    Optical test strip based on the use of Br-PADAP as a sensitive reagent immobilised into sol-gel thin film for detection of Hg(II) in aqueous solution had been thoroughly carried out. It has a square-sensing zone (1.0 cm x 1.0 cm) containing the sensitive reagent necessary to produce response to trace level of mercury. This method offer sensitivity and simplicity in detecting Hg(II) as no prior treatment or extraction is required. A linear response was attained in the Hg(II) concentration in the range of 0.5-2.5 ppm with calculated limit of detection of 6.63 ppb. This method also showed a reproducible result with relative standard deviation (R.S.D.) of 2.15% and response time of approximately 5 min. Interference studies showed that Al(III), Co(II) and Ni(II) significantly interfered during the determination. The developed sensor has been validated against Atomic Absorption Spectroscopy method and proven comparable.
    Matched MeSH terms: Reagent Strips/chemistry*
  3. Makhsin SR, Razak KA, Noordin R, Zakaria ND, Chun TS
    Nanotechnology, 2012 Dec 14;23(49):495719.
    PMID: 23164811 DOI: 10.1088/0957-4484/23/49/495719
    This study describes the properties of colloidal gold nanoparticles (AuNPs) with sizes of 20, 30 and 40 nm, which were synthesized using citrate reduction or seeding-growth methods. Likewise, the conjugation of these AuNPs to mouse anti-human IgG(4) (MαHIgG(4)) was evaluated for an immunochromatographic (ICG) strip test to detect brugian filariasis. The morphology of the AuNPs was studied based on the degree of ellipticity (G) of the transmission electron microscopy images. The AuNPs produced using the seeding-growth method showed lower ellipticity (G ≤ 1.11) as compared with the AuNPs synthesized using the citrate reduction method (G ≤ 1.18). Zetasizer analysis showed that the AuNPs that were synthesized using the seeding-growth method were almost monodispersed with a lower polydispersity index (PDI; PDI≤0.079), as compared with the AuNPs synthesized using the citrate reduction method (PDI≤0.177). UV-visible spectroscopic analysis showed a red-shift of the absorbance spectra after the reaction with MαHIgG(4), which indicated that the AuNPs were successfully conjugated. The optimum concentration of the BmR1 recombinant antigen that was immobilized on the surface of the ICG strip on the test line was 1.0 mg ml(-1). When used with the ICG test strip assay and brugian filariasis serum samples, the conjugated AuNPs-MαHIgG(4) synthesized using the seeding-growth method had faster detection times, as compared with the AuNPs synthesized using the citrate reduction method. The 30 nm AuNPs-MαHIgG(4), with an optical density of 4 from the seeding-growth method, demonstrated the best performance for labelling ICG strips because it displayed the best sensitivity and the highest specificity when tested with serum samples from brugian filariasis patients and controls.
    Matched MeSH terms: Reagent Strips*
  4. Ng KP, Saw TL, Baki A, He J, Singh N, Lyles CM
    Int J STD AIDS, 1999 Jun;10(6):401-4.
    PMID: 10414883
    Hema-Strip HIV-1/2 is a one-step rapid test for the detection of anti-HIV-1/2 antibodies in whole blood. The test requires no expensive equipment and the results are available within 10-15 min. Using 72 known HIV-1 positive samples and 780 high-risk prisoners, the sensitivity and specificity of Hema-Strip HIV-1/2 was found to be comparable to microparticle enzyme immunoassay (MEIA). The data also indicated that Hema-Strip HIV-1/2 is an effective alternate testing system to conventional ELISA where the use of ELISA is not suitable and the result of the HIV testing is needed urgently.
    Matched MeSH terms: Reagent Strips*
  5. Ullah A, Barman A, Ahmed I, Salam A
    J Obstet Gynaecol, 2012 Jan;32(1):37-41.
    PMID: 22185534 DOI: 10.3109/01443615.2011.601697
    In Bangladesh, a number of screening tests for asymptomatic bacteriuria in pregnancy are in practice. The objective of this study was to assess the validity and cost-effectiveness of these screening tests. A total of 600 apparently healthy pregnant mothers were included in this study. The validity of the screening tests was calculated against the urine culture as 'gold standard'. Incremental cost-effective ratio between the screening test methods and the least costly method (microscopic urine analysis) was calculated. Bacterial count/oil-immersion field in Gram-stained smear of urine was the most sensitive (91.7%) and specific (97.2%). Incremental cost per additional positive cases of bacterial count, leukocyte esterase and combination of leukocyte esterase and nitrite were US$3, US$25 and US$23, respectively. Gram staining may be the alternative approach to traditional routine urinalysis for the screening of asymptomatic bacteriuria during pregnancy in clinical practice in Bangladesh, as well as other developing countries.
    Matched MeSH terms: Reagent Strips
  6. Nurulfiza I, Hair-Bejo M, Omar AR, Aini I
    J. Vet. Diagn. Invest., 2011 Mar;23(2):320-4.
    PMID: 21398455
    The immunochromatographic assay is an alternative method for simple and rapid detection of Infectious bursal disease virus (IBDV) in chickens using colloidal gold-antibody conjugate. The whole-virus antigen of IBDV (UPM04190 isolate) and the high-affinity polyclonal antibodies directed against IBDV were blotted onto nitrocellulose membranes for test and control lines, respectively. Evaluation of the strip was performed using serum samples from experimentally and naturally infected chickens. The results showed that the test strip was more sensitive than the commercial enzyme-linked immunosorbent assay (ELISA) because it could detect a dilution factor up to 120,000 (250 ELISA units) for positive samples. It was also specific, in that it detected IBDV antibodies and did not cross-react with antibodies to other chicken viruses. The method was rapid (2 min) in both clinical and field environments with samples needing only a minimum amount (50 µl) of blood to produce an acceptable detection signal. The pen-site test strip proved successful in monitoring the immune status of chickens against the IBDV infection.
    Matched MeSH terms: Reagent Strips*
  7. Rohani MY, Hasnidah D, Ong KH
    Malays J Pathol, 1998 Jun;20(1):31-3.
    PMID: 10879261
    A chromatographic immunoassay cholera antigen detection kit, the Cholera Spot test, was evaluated. The test was found to be specific with a sensitivity of 10(6) cfu/ml for the direct detection of V. cholerae in simulated stool specimens and 10 cfu/ml in simulated cotton-tipped swab specimens after overnight incubation in alkaline peptone water. This enables early recognition of cholera cases and their contacts so that prevention and control measures can be promptly instituted.
    Matched MeSH terms: Reagent Strips*
  8. Saidin S, Yunus MH, Zakaria ND, Razak KA, Huat LB, Othman N, et al.
    BMC Infect. Dis., 2014 Apr 04;14:182.
    PMID: 24708664 DOI: 10.1186/1471-2334-14-182
    BACKGROUND: Amoebic liver abscess (ALA) is the most common clinical manifestation of extraintestinal amoebiasis especially in developing countries, causing up to 100 000 fatal cases annually. Accurate and early diagnosis is important to prevent the disease complications, however its diagnosis still poses many challenges due to the limitations of the available detection tools. Pyruvate phosphate dikinase (PPDK), an excretory-secretory protein of E. histolytica, has been reported as a potential diagnostic marker for ALA, hence it may be exploited in the development of a new test for ALA.

    METHODS: Recombinant PPDK (rPPDK) was expressed, purified and evaluated by Western blot. In parallel, recombinant galactose-and-N-acetyl-D-galactosamine inhibitable lectin (Gal/GalNAc lectin) was produced and tested similarly. The protein identity was confirmed by analysis using MALDI-TOF/TOF. A lateral flow dipstick (LFD) test using rPPDK was subsequently developed (rPPDK-LFD) and evaluated for serodiagnosis of ALA.

    RESULTS: rPPDK was expressed as soluble protein after 4 hours of induction with 1 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) at 30°C. Purification using nickel-nitrilotriacetic acid (Ni-NTA) resin yielded 1.5 mg of rPPDK from 1 L of culture with estimated molecular mass of 98 kDa on SDS-PAGE. Western blots using sera from patients with ALA, healthy individuals and other diseases probed with anti-human IgG4-HRP showed the highest sensitivity (93.3%) and specificity (100%); as compared to blots using IgG and IgG1 as secondary antibodies. Moreover, rPPDK showed better specificity when compared to rGal/GalNAc lectin. In the development of the LFD test, the optimum amount of rPPDK was 0.625 μg per dipstick and the optimum working concentration of colloidal gold conjugated anti-human IgG4 was optical density (OD) 5 (1.7 μg of anti-human IgG4). Evaluation of rPPDK-LFD using ALA patients and controls serum samples showed 87% diagnostic sensitivity and 100% specificity.

    CONCLUSION: The developed rPPDK-LFD showed good potential for rapid diagnosis of ALA, and merit further multicentre validation using larger number of serum samples.

    Matched MeSH terms: Reagent Strips/chemistry*
  9. Ang GY, Yu CY, Yean CY
    Biosens Bioelectron, 2012 Oct-Dec;38(1):151-6.
    PMID: 22705404 DOI: 10.1016/j.bios.2012.05.019
    In the field of diagnostics, molecular amplification targeting unique genetic signature sequences has been widely used for rapid identification of infectious agents, which significantly aids physicians in determining the choice of treatment as well as providing important epidemiological data for surveillance and disease control assessment. We report the development of a rapid nucleic acid lateral flow biosensor (NALFB) in a dry-reagent strip format for the sequence-specific detection of single-stranded polymerase chain reaction (PCR) amplicons at ambient temperature (22-25°C). The NALFB was developed in combination with a linear-after-the-exponential PCR assay and the applicability of this biosensor was demonstrated through detection of the cholera toxin gene from diarrheal-causing toxigenic Vibrio cholerae. Amplification using the advanced asymmetric PCR boosts the production of fluorescein-labeled single-stranded amplicons, allowing capture probes immobilized on the NALFB to hybridize specifically with complementary targets in situ on the strip. Subsequent visual formation of red lines is achieved through the binding of conjugated gold nanoparticles to the fluorescein label of the captured amplicons. The visual detection limit observed with synthetic target DNA was 0.3 ng and 1 pg with pure genomic DNA. Evaluation of the NALFB with 164 strains of V. cholerae and non-V. cholerae bacteria recorded 100% for both sensitivity and specificity. The whole procedure of the low-cost NALFB, which is performed at ambient temperature, eliminates the need for preheated buffers or additional equipment, greatly simplifying the protocol for sequence-specific PCR amplicon analysis.
    Matched MeSH terms: Reagent Strips/analysis
  10. Ng LC, Teng LC, Ng ML, Sazali BS, Khalid BA
    Malays J Pathol, 2000 Dec;22(2):73-8.
    PMID: 16329538
    Detection of microalbuminuria is important in the management of diabetic patients since it is predictive of development of proteinuria and nephropathy. Two sensitive and specific in-house ELISAs for microalbuminuria were established and validated. One of the ELISAs was based on antigen coating while the other employed antibody coating. Recovery and linearity experiments gave acceptable results of 100 +/- 10%, while precision results were <10% for intra-assay and <12% for inter-assay coefficients of variation (CVs). The standard curve ranged from 10-625 ug/l, equivalent to 0.2-12.5 mg/l for urine samples diluted 1:20 fold. When the antibody coated ELISA was compared to antigen coated ELISA, a correlation of r=0.996 was obtained. When compared to commercial kits, the in-house ELISAs gave good correlations of r=0.961 versus the Boehringer Mannheim Micral Test strips and r=0.940 versus Ames Microalb Turbidimetry. The normal microalbumin reference ranges determined for 12h, first morning and random urine samples were 0.7-5.3 mg, 0.1-10.2 mg/l and 0.8-26.1 mg/l respectively. The normal albumin excretion rate (AER) was 1.0-7.3 ug/min while untimed urine samples gave results of 0.1-0.9 and 0.2-1.6 mg/mmol after dividing by creatinine concentrations. The ELISAs were used to detect microalbuminuria in 338 random urine samples from diabetic patients. A high percentage 47.9% was found to be positive for microalbuminuria and 18.0% had macroalbuminuria >25 mg/mmol. Thus screening for microalbuminuria together with creatinine measurements using random urine samples can be used for management of diabetic patients.
    Matched MeSH terms: Reagent Strips
  11. Jamail M, Andrew K, Junaidi D, Krishnan AK, Faizal M, Rahmah N
    Trop. Med. Int. Health, 2005 Jan;10(1):99-104.
    PMID: 15655019
    We conducted a field study of a rapid test (Brugia Rapid) for detection of Brugia malayi infection to validate its sensitivity and specificity under operational conditions. Seven districts in the state of Sarawak, Malaysia, which are endemic for brugian filariasis, were used to determine the test sensitivity. Determination of specificity was performed in another state in Malaysia (Bachok, Kelantan) which is non-endemic for filariasis but endemic for soil-transmitted helminths. In Sarawak both the rapid test and thick blood smear preparation were performed in the field. The rapid test was interpreted on site, whereas blood smears were taken to the district health centres for staining and microscopic examination. Sensitivity of Brugia Rapid dipstick as compared with microscopy of thick blood smears was 87% (20/23; 95% CI: 66.4-97.2) whereas the specificity was 100% (512/512). The lower sensitivity of the test in the field than in laboratory evaluations (> or =95%), was probably due to the small number of microfilaraemic individuals, in addition to difficulties in performing the test in remote villages by field personnel. The overall prevalence of brugian filariasis as determined by the dipstick is 9.4% (95% CI: 8.2-0.5) while that determined by microscopy is 0.90% (95% CI: 0.5-1.3) thus the dipstick detected about 10 times more cases than microscopy. Equal percentages of adults and children were found to be positive by the dipstick whereas microscopy showed that the number of infected children was seven times less than infected adults. The rapid dipstick test was useful as a diagnostic tool for mapping and certification phases of the lymphatic filariasis elimination programme in B. malayi-endemic areas.
    Matched MeSH terms: Reagent Strips
  12. Lee SW, Liong ML, Yuen KH, Leong WS, Khan N, Cheah PY, et al.
    Urol. Int., 2009;82(1):32-7.
    PMID: 19172094 DOI: 10.1159/000176022
    BACKGROUND: Little is known about how primary care physicians (PCPs) in Asia diagnose and manage prostatitis-like symptoms. This study investigated the clinical diagnosis of and care provided for prostatitis-like symptoms by PCPs in a Malaysian population, and compared these findings to reports from other areas.
    METHODS: All members of the Penang Private Medical Practitioners' Society were asked to complete a self-administered survey. Nonresponders were contacted after 3 weeks and received a telephone request after 6 weeks.
    RESULTS: Of the 786 practitioners contacted, 669 considered themselves to be PCPs, including 279 (42%) who responded to the survey. Adult males with prostatitis-like symptoms typically constitute <1% of the patients seen by PCPs. Most PCPs (72%) believe that prostatitis-like symptoms are caused by bacterial infection. 61% of PCPs base their diagnosis of prostatitis-like symptoms on clinical history, a physical examination and dipstick urinalysis. Standard management was to prescribe 1 or 2 courses of antimicrobials.
    CONCLUSIONS: Despite the 8.7% prevalence found in a previous survey in this population, prostatitis remains underdiagnosed in Malaysia. In contrast to many other clinical settings, urologists in Malaysia see a large proportion of newly diagnosed and treatment-naive prostatitis patients, providing an opportunity for clinical diagnostic and treatment studies.
    Matched MeSH terms: Reagent Strips
  13. Saidin S, Yunus MH, Othman N, Lim YA, Mohamed Z, Zakaria NZ, et al.
    Pathog Glob Health, 2017 May;111(3):128-136.
    PMID: 28335696 DOI: 10.1080/20477724.2017.1300421
    Entamoeba histolytica infection remains a public health concern in developing countries. Early diagnosis of amoebiasis can avoid disease complications, thus this study was aimed at developing a test that can rapidly detect the parasite antigens in stool samples. Rabbits were individually immunized with recombinant pyruvate phosphate dikinase (rPPDK) and E. histolytica excretory-secretory antigens to produce polyclonal antibodies. A rapid dipstick test was produced using anti-rPPDK PAb lined on the dipstick as capture reagent and anti-EhESA PAb conjugated to colloidal gold as the detector reagent. Using E. histolytica-spiked in stool sample of a healthy individual, the detection limit of the dipstick test was found to be 1000 cells ml-1. Meanwhile when rPPDK was spiked in the stool sample, the minimum concentration detected by the dipstick test was 0.1 μg ml-1. The performances of the dipstick, commercial Techlab E. histolytica II enzyme-linked immunosorbent assays (ELISA) and real-time PCR were compared using 70 stool samples from patients infected with Entamoeba species (n = 45) and other intestinal pathogens (n = 25). When compared to real-time PCR, the diagnostic sensitivity of the dipstick for detection of E. histolytica was 65.4% (n = 17/26); while the diagnostic specificity when tested with stool samples containing other intestinal pathogens was 92% (23/25). In contrast, Techlab E. histolytica II ELISA detected 19.2% (5/26) of the E. histolytica-positive samples as compared to real-time PCR. The lateral flow dipstick test produced in this study enabled rapid detection of E. histolytica, thus it showed good potential to be further developed into a diagnostic tool for intestinal amoebiasis.
    Matched MeSH terms: Reagent Strips
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