Displaying publications 1 - 20 of 45 in total

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  1. Aziz AFE, Roshidi N, Muhammad Hanif MDH, Tye GJ, Arifin N
    Clin Chim Acta, 2024 Jul 15;561:119839.
    PMID: 38964570 DOI: 10.1016/j.cca.2024.119839
    Immunoassays are important tools in diagnosing giardiasis, though there are several controversies inherent in the existing methods. We conducted a systematic review and meta-analysis to assess the pooled diagnostic accuracy of immunoassays in detecting the gastrointestinal disease-causing parasite Giardia lamblia. Our comprehensive search, which included PubMed, Scopus, and ScienceDirect from 2000 up until 2023, resulted in 34 studies reporting the performance of 24 different immunoassays. The overall pooled sensitivity and specificity of immunoassays and subgroup analyses were determined. Notably, ImmunoCardSTAT® and RIDASCREEN® Giardia were the most used assays (n = 6 studies each). They exhibited sensitivity and specificity of 84 % and 99 % and 93 % and 99 %, respectively. Sub-group analysis on the type of immunoassays (without the case-control studies) showed that commercial ELISA had higher sensitivity (96 %) compared to a commercial immunochromatographic (88 %), which justifies the difference of sensitivity between ImmunoCardSTAT® and RIDASCREEN® Giardia. However, the applicability between these two in clinical settings, replacing the gold standard, should be considered including the time, equipment requirement, and budget. Samples from symptomatic patients showed higher sensitivity (92 %) compared to asymptomatic patients (79 %). Overall, immunoassays can be a practical replacement for the current gold standard, but more information should be gathered regarding the cost of providing more conclusive suggestions on these findings.
    Matched MeSH terms: Immunoassay/methods
  2. Mohd Zain R, Shaiful Bahrin NI, Ellan K, Thayan R
    Malays J Pathol, 2021 Dec;43(3):463-464.
    PMID: 34958069
    No abstract available.
    Matched MeSH terms: Immunoassay/methods*
  3. Liew WP, Sabran MR
    J Food Drug Anal, 2022 Nov 23;30(4):549-561.
    PMID: 36753365 DOI: 10.38212/2224-6614.3430
    The co-occurrence and accumulation of mycotoxin in food and feed constitutes a major issue to food safety, food security, and public health. Accurate and sensitive mycotoxins analysis can avoid toxin contamination as well as reduce food wastage caused by false positive results. This mini review focuses on the recent advance in detection methods for multiple mycotoxins, which mainly depends on immunoassay technologies. Advance immunoassay technologies integrated in mycotoxin analysis enable simultaneous detection of multiple mycotoxins and enhance the outcomes' quality. It highlights toxicogenomic as novel approach for hazard assessment by utilizing computational methods to map molecular events and biological processes. Indeed, toxicogenomic is a powerful tool to understand health effects from mycotoxin exposure as it offers insight on the mechanisms by which mycotoxins exposures cause diseases.
    Matched MeSH terms: Immunoassay/methods
  4. Loh Q, Omar N, Glökler J, Lim TS
    Anal Biochem, 2014 Oct 15;463:67-9.
    PMID: 24972268 DOI: 10.1016/j.ab.2014.06.012
    Immunoassays are often coupled to peroxidase activity for antigen detection. Sensitivity and speed of detection has been increased by the advent of hybrid methods such as immuno-PCR (polymerase chain reaction). However, a more simplified immunoassay that retains both colorimetric peroxidase detection and effective DNA amplification in a setting closer to field application conditions has been nonexistent. Here we describe a method that successfully combines a competitive immunoassay with the new isothermal quadruplex-primed amplification (QPA) to generate excess quadruplex reporter molecules with intrinsic peroxidase DNAzyme activity.
    Matched MeSH terms: Immunoassay/methods*
  5. Lopez JB, Peng CL
    Clin Chem Lab Med, 2003 Oct;41(10):1369-72.
    PMID: 14580168
    The concentration of homocysteine (Hcy) rises rapidly after the collection of blood. This feature requires blood to be collected into the anticoagulants EDTA or heparin and the plasma to then be immediately separated; alternatively, the blood may be kept on ice and centrifuged within 1 hour. The use of chemical preservatives has been proposed as a means of stabilising Hcy levels in whole blood after collection. The objective of this study was to determine whether the commonly available fluoride-oxalate (Fl-Ox) and sodium citrate (Na-Cit) containers could stabilise Hcy levels in blood. Our results showed that when blood was collected into potassium EDTA (K-EDTA) tubes, Hcy levels rose from initial levels, on standing at room temperature (approximately 25 degrees C), by an average of 21% after 3 hours and 32% after 5 hours. The initial Hcy levels of blood collected into Fl-Ox and Na-Cit containers, however, were lower, at averages of 89% and 91%, respectively, compared to that of the same samples when collected into K-EDTA tubes. Hcy in these samples subsequently rose on standing, and after 5 hours was, on the average, 10 and 13% higher, respectively, compared with the initial levels in K-EDTA tubes. We conclude that Fl-Ox and Na-Cit do not stabilise Hcy in blood after collection and should not be used as preservatives.
    Matched MeSH terms: Immunoassay/methods*
  6. Jambari NN, Wang X, Alcocer M
    Methods Mol Biol, 2017;1592:129-137.
    PMID: 28315216 DOI: 10.1007/978-1-4939-6925-8_10
    Protein microarray is a miniaturized multi-analyte, solid-phased immunoassay where thousands of immobilized individual protein spots on a microscopic slide bind are bound to specific antibodies (immunoglobulins) from serum samples, which are then detected by fluorescent labeling. The image processing and pattern recognition are then quantitatively analyzed using advanced algorithms. Here, we describe the use of an in-house-produced complex protein microarray containing extracts and pure proteins that has been probed with antibodies present in the horse sera and detection by fluorophore-conjugated antibody and data analysis. The flexibility of the number and types of proteins that can be printed on the microarray allows different set of specific IgE immunoassay analysis to be carried out.
    Matched MeSH terms: Immunoassay/methods
  7. Yang H, Zhang Z, Zhou X, Binbr Abe Menen N, Rouhi O
    Environ Res, 2023 Dec 01;238(Pt 1):117163.
    PMID: 37722583 DOI: 10.1016/j.envres.2023.117163
    The current study has focused on electrochemical immunosensing of carcinoembryonic antigen (CEA) employing an immobilized antibody on a thionine, chitosan, or graphene oxide nanocomposite modified glassy carbon electrode (anti-CEA/THi-CS-GO/GCE) as an indicator of cancer monitoring. THi-CS-GO nanocomposites were made using ultrasonication, and analyses of their morphology and crystal structure using SEM, FTIR, and XRD showed that thionine and chitosan molecules were intercalated with stacking interactions with both the top and bottom of GO nanosheets. Electrochemical experiments revealed anti-CEA, THi-CS-GO/GCE to have exceptional sensitivity and selectivity towards CEA compounds. The detection limit value was established to be 0.8 pg/mL when it was discovered that variations in the decrease peak current were directly proportional to the logarithm concentration of CEA over a wide range from 10-3 to 104 ng/mL. Results of testing the immunosensor's application capability for detecting CEA in a sample of human serum show that ELISA and DPV results are very congruent. The produced immunosensor demonstrated adequate immunosensor precision in determining CEA in prepared genuine samples of human serum and clinical applications.
    Matched MeSH terms: Immunoassay/methods
  8. Lim EW, Meers PD
    Ann Acad Med Singap, 1989 Jul;18(4):348-51.
    PMID: 2679337
    A rapid method of assay, using a monoclonal antibody linked to alkaline phosphatase, was used for the detection of the Pontiac subgroup of Legionella pneumophila serogroup 1. It was tested for its specificity against 53 strains of Legionella recently isolated from the environment in Singapore and Malaysia. The specificity and sensitivity of this method of assay was confirmed, though there is some concern that the specificity was too narrow, and there are reservations about the criteria suggested for interpreting the results.
    Matched MeSH terms: Immunoassay/methods
  9. Yoo SJ, Wang LL, Ning HC, Tao CM, Hirankarn N, Kuakarn S, et al.
    J Clin Virol, 2015 Mar;64:20-7.
    PMID: 25728074 DOI: 10.1016/j.jcv.2014.12.015
    Early diagnosis of hepatitis C virus (HCV) infection is essential to allow appropriate treatment and prevent transmission.
    Matched MeSH terms: Immunoassay/methods*
  10. Ng BK, Lim PS, Shafiee MN, Ghani NA, Ismail NA, Omar MH, et al.
    Biomed Res Int, 2013;2013:587438.
    PMID: 24073412 DOI: 10.1155/2013/587438
    Objective. To determine the diagnostic accuracy of placental alpha microglobulin-1 assay and standard diagnostic methods for detecting rupture of membrane. Study Design. Prospective diagnostic study, between June 2011 to November 2011 at a tertiary centre. Initial evaluation included both the standard diagnostic methods for rupture of membranes and placental alpha microglobulin-1 immunoassay. The actual rupture of membranes was diagnosed on review of the medical records after delivery (absence of membrane or a positive pad chart). Main Outcome Measures. Placental alpha microglobulin-1 immunoassay and standard diagnostic methods for diagnosis of rupture of membrane. Results. A total of 211 patients were recruited. At initial presentation, 187 patients (88.6%) had ruptured membranes, while 24 patients (11.4%) had intact membranes. Placental alpha microglobulin-1 immunoassay confirmed rupture of membranes at initial presentation with a sensitivity of 95.7% (179 of 187), specificity of 100% (24 of 24), positive predictive value of 100% (179 of 179), and negative predictive value of 75.0% (24 of 32). By comparison, the conventional standard diagnostic methods had a sensitivity of 78.1% (146 of 187), specificity of 100% (24 of 24), positive predictive value of 100% (146 of 146), and negative predictive value of 36.9% (24 of 65) in diagnosing rupture of membrane. Conclusion. Placental alpha-microglobulin-1 immunoassay is a rapid and accurate method for confirming the diagnosis of rupture of membrane. It was superior to conventional standard diagnostic methods (pooling, nitrazine, and ferning), the nitrazine test alone or fern test alone.
    Matched MeSH terms: Immunoassay/methods*
  11. Yeang HY, Arif SA, Raulf-Heimsoth M, Loke YH, Sander I, Sulong SH, et al.
    J Allergy Clin Immunol, 2004 Sep;114(3):593-8.
    PMID: 15356563 DOI: 10.1016/j.jaci.2004.05.039
    BACKGROUND:
    Sensitization to natural rubber latex has been linked to proteins from medical latex gloves. Various assays to estimate the amount of residual allergenic proteins extractable from latex gloves to assess their potential exposure hazard have inherent weaknesses.

    OBJECTIVE:
    This investigation was aimed at developing 2-site immunoenzymetric assays and identifying appropriate protein markers to assess the allergenic potential of latex gloves.

    METHODS:
    The presence of 6 latex allergens--Hev b 1, 2, 3, 5, 6, and 13--was measured in a cross-section of commercial latex medical gloves by using monoclonal and polyclonal antibody-based 2-site immunoenzymetric assays. The overall allergenic potential of these gloves was assessed by IgE-inhibition assay. Stepwise multiple regression analyses were performed to identify marker allergens that best explained the variation in latex glove allergenicity.

    RESULTS:
    All 6 latex allergens were detected in at least some of the glove samples. Hev b 5 and Hev b 13 were identified as the marker allergens that combined best to explain the variation in the glove allergenicity. The significant multiple correlation (R=0.855) between these 2 markers and glove allergenic potency forms the basis of an assay to gauge latex glove allergenicity.

    CONCLUSION:
    The overall allergenic potential of latex gloves can be estimated by using Hev b 5 and Hev b 13 as indicator allergens. The correlation between glove allergenicity and the level of these allergens was maintained for low-protein gloves (<200 microg/g). This estimation of glove allergenicity was superior to that obtained by using total protein readings.
    Matched MeSH terms: Immunoassay/methods
  12. Ho TM, DeBruynne J, Ahamad M, Darussamin H
    Asian Pac J Allergy Immunol, 1997 Sep;15(3):123-6.
    PMID: 9438543
    The MAST CLA system was evaluated against skin prick test (SPT) for diagnosis of allergies to house dust mites (Dermatophagoides pteronyssinus, Dermatophagoides farinae) and cats. Forty three asthmatic children were examined by SPT and MAST CLA. Chi-square analysis indicated significant association between SPT and MAST CLA results for the house dust mites but not for cats. The sensitivities of MAST CLA for house dust mites and cats were 100 and 25% respectively; specificities were all less than 50%. The efficiency of MAST CLA for detection of allergy to the house dust mites was 88% and 44% for cats. A significant linear correlation was found between SPT wheal size and MAST CLA grade for D. farinae but not for D. pteronyssinus and cats. It is concluded that the MAST CLA allergy system can be used to supplement SPT for diagnosis of allergies to house dust mites but not to cats.
    Matched MeSH terms: Immunoassay/methods*
  13. Rahmah N, Anuar AK, A'shikin AN, Lim BH, Mehdi R, Abdullah B, et al.
    Biochem Biophys Res Commun, 1998 Sep 29;250(3):586-8.
    PMID: 9784388
    Western blot analyses were performed on 444 serum specimens: 40 sera from microfilaraemic individuals, 10 sera from elephantiasis patients, 24 treated individuals, 50 sera from residents of endemic areas without anti-filarial IgG4 antibodies (endemic normals), 20 sera from amicrofilaraemic individuals with high anti-filarial IgG4 antibodies, 200 sera from healthy city-dwellers (non-endemic samples), and 100 sera from soil-transmitted helminth-infected individuals. Phast electrophoresis system was used to electrophorese Brugia malayi soluble adult worm antigen on 10-15% SDS-PAGE gradient gels followed by electrophoretic transfer onto PVDF membranes. Membrane strips were then successively incubated with blocking solution, human sera, and monoclonal anti-human IgG4 antibody-HRP, with adequate washings done in between each incubation step. Luminol chemiluminescence detection was then used to develop the blots. An antigenic band with the MW of approximately 37 kDa was found to be consistently present in the Western blots of all microfilaraemic sera, all amicrofilaraemic sera with high titres of anti-filarial IgG4 antibodies, some treated patients, and some elephantiasis patients. The antigen did not occur in immunoblots of individuals with other helminthic infections, normal endemic individuals, and city dwellers. Therefore the B. malayi antigen of with the MW of approximately 37 kDa demonstrated specific reactions with sera of B. malayi-infected individuals and thus may be useful for diagnostic application.
    Matched MeSH terms: Immunoassay/methods
  14. Alia SN, Joseph N, Philip N, Azhari NN, Garba B, Masri SN, et al.
    J Infect Public Health, 2018 11 27;12(2):263-269.
    PMID: 30502041 DOI: 10.1016/j.jiph.2018.10.137
    BACKGROUND: Leptospirosis is often misdiagnosed with several other tropical febrile illnesses in Malaysia due to similarities in clinical manifestations. Although treatment regimens could be started based on clinical judgments, early diagnosis has become paramount as a guide to chemotherapeutic interventions. Confirmed laboratory diagnosis through MAT or PCR is time consuming and usually available only in reference laboratories and not practical in healthcare settings. Rapid and easy to perform diagnostic tests are widely used in these settings as the point of care diagnosis. The present study was undertaken to compare the diagnostic performance of two IgM based immunodiagnostic assay kits for acute leptospirosis.

    METHODS: A total of 50 serum samples were collected from patients clinically suspected for acute leptospirosis on admission in the Hospital Serdang, from June 2016 to June 2017. All the samples were subjected to MAT, lipL32 PCR and the two rapid tests (Leptocheck-WB and ImmuneMed Leptospira IgM Duo Rapid test).

    RESULTS: Out of the 50 clinically suspected patients sampled, 19 were confirmed positive for leptospirosis. Six (12%) were confirmed by MAT and 13 (26%) by PCR. Similarly, of the 50 clinically suspected cases, 17 (34%) showed positivity for Leptocheck-WB and 7 (14%) for ImmuneMed Leptospira IgM Duo Rapid test. The overall sensitivity and specificity was 47.37% and 80.65% for Leptocheck-WB, and 21.05% and 90.32% for ImmuneMed Leptospira IgM Duo Rapid test. In another set of previously confirmed MAT positive samples (1:400-1:3600) obtained from a reference laboratory, Leptocheck-WB showed higher sensitivity (90.72%) than ImmuneMed Leptospira IgM Duo Rapid test (40.21%), and comparable specificity for ImmuneMed Leptospira IgM Duo Rapid test (88.89%) and Leptocheck-WB (82.86%).

    CONCLUSION: The sensitivity was higher for Leptocheck-WB and had a comparable specificity with ImmuneMed Leptospira IgM Duo Rapid test. Therefore, based on the present study, Leptocheck-WB is found to be a more sensitive rapid immunodiagnostic test for acute leptospirosis screening in hospital settings.

    Matched MeSH terms: Immunoassay/methods*
  15. Ali N, Hashim NH, Saad B, Safan K, Nakajima M, Yoshizawa T
    Food Chem Toxicol, 2005 Dec;43(12):1763-72.
    PMID: 16019122
    Traditional herbal medicines, popularly known as 'jamu' and 'makjun' in Malaysia and Indonesia, are consumed regularly to promote health. In consideration of their frequent and prolonged consumption, the natural occurrence of aflatoxins (AF) in these products was determined using immunoaffinity column clean-up and high-performance liquid chromatography with pre-column derivatization. The evaluated method, which entails dilution of sample extracts with Tween 20-phosphate buffered saline (1:9, v/v) and a chromatographic system using isocratic mobile phase composed of water-methanol-acetonitrile (70:20:10, v/v/v), was effective in separating AFB1, AFG1 and AFG2 from interference at their retention times. Results were confirmed using post-column derivatization with photochemical reactor. For 23 commercial samples analyzed, mean levels (incidence) of AFB(1), AFB(2) and AFG1 in positive samples were 0.26 (70%), 0.07 (61%) and 0.10 (30%) microg/kg, respectively; one sample was positive for AFG2 at a level of 0.03 (4%) microg/kg. In contrast to the high levels of AF in crude herbal drugs and medicinal plants reported previously by other researchers, the low contamination levels reported in this study may be attributed to the higher selectivity to AF of the method applied. Based on the AFB1 levels and the daily consumption of positive samples, a mean probable daily intake of 0.022 ng/kg body weight was calculated.
    Matched MeSH terms: Immunoassay/methods
  16. Ting HY, Sthaneshwar P, Bee PC, Shanmugam H, Lim M
    Pathology, 2019 Aug;51(5):507-511.
    PMID: 31253381 DOI: 10.1016/j.pathol.2019.04.002
    Serum protein (SPE) and immunofixation electrophoresis (IFE) have been extensively validated for the routine use of identifying, characterising and quantifying monoclonal proteins. However, accurate quantitation of IgA monoclonal proteins can be difficult when they migrate in to the β fraction, due to co-migration with transferrin and complement components. The heavy/light chain (HLC) immunoassay is an additional tool for measuring intact immunoglobulin monoclonal proteins. Therefore, we aimed to examine the clinical utility of the HLC assay for the disease monitoring of IgG and IgA multiple myeloma (MM) patients. A total of 177 samples from 30 MM patients (21 IgG and 9 IgA) were analysed retrospectively with median number of six follow up samples per patient (range 3-13). Serum free light chains (sFLC) and HLC were quantified using Freelite and Hevylite immunoassays. Details of M-protein concentration, β-globulin levels, total immunoglobulin levels and disease treatment response were obtained from the laboratory and patient information system. Passing-Bablok regression analysis was performed to compare (i) M-protein quantification with involved HLC (iHLC) and (ii) total immunoglobulin with summated HLC pairs for each immunoglobulin type (e.g., IgGκ+IgGλ). For 127 IgG MM samples, IgG iHLC levels showed a good correlation with SPE quantification (iHLC y=0.96x+4.9; r=0.917) and summated HLC showed a good correlation with total IgG concentration (summated HLC y=0.94x+5.74; r=0.91). In total, 95/127 (75%) IgG MM follow-up samples had an abnormal HLC ratio and 122/127 (96%) had a positive SPE, probably due to the lower sensitivity of HLC assay in detecting clonality in patients with IgG MM. Consistent with this, one patient assigned a very good partial response by International Myeloma Working Group criteria would be assigned a complete response based on HLC measurements. For 50 IgA MM samples, 42/50 (84%) had an abnormal HLC ratio. Conversely, 50/50 (100%) of M-proteins showed β fraction migration and were difficult to accurately quantify by SPE. Therefore, M-protein concentration and iHLC did not correlate as well in IgA MM (y=1.9x-8.4; r=0.8) compared to IgG MM. However, there was good correlation between total IgA and summated IgA HLC (IgAκ+IgAλ y=1.35x-0.33; r=0.95). Of the 8/50 (16%) IgA samples with a normal HLC ratio, 6/8 (75%) were consistent with the disease status being in complete remission. Interestingly, in one IgA MM patient, SPE and IFE were negative, but the serum FLC ratio and involved FLC were highly abnormal, consistent with the presence of light chain escape. Our data suggest HLC measurements could add value to the current disease monitoring of MM patients. In IgG MM patients, the M-protein level correlated well with HLC values. The HLC assay complements the serum FLC assay and is especially useful for monitoring of IgA MM patients who display M-proteins migrating in the β region on SPE.
    Matched MeSH terms: Immunoassay/methods*
  17. Mohd Azmi UZ, Yusof NA, Abdullah J, Alang Ahmad SA, Mohd Faudzi FN, Ahmad Raston NH, et al.
    Mikrochim Acta, 2021 01 06;188(1):20.
    PMID: 33404779 DOI: 10.1007/s00604-020-04669-x
    An early detection of Mycobacterium tuberculosis is very important to reduce the number of fatal cases and allow for fast recovery. However, the interpretation of the result from smear microscopy requires skilled personnel due to the propensity of the method to produce false-negative results. In this work, a portable, rapid, and simple sandwich-type immunosensor reader has been developed that is able to detect the presence of M. tuberculosis in sputum samples. By using sandwich-type immunosensor, an anti-CFP10-ESAT6 antibody was immobilized onto the graphene/polyaniline (GP/PANI)-modified gold screen-printed electrode. After incubation with the target CFP10-ESAT6 antigen, the iron/gold magnetic nanoparticles (Fe3O4/Au MNPs) conjugated with anti-CFP10-ESAT6 antibody were used to complete the sandwich format. Differential pulse voltammetry (DPV) technique was used to detect the CFP10-ESAT6 antigen at the potential range of 0.0-1.0 V. The detection time is less than 2 h. Under optimal condition, CFP10-ESAT6 antigen was detected in a linear range from 10 to 500 ng mL-1 with a limit of detection at 1.5 ng mL-1. The method developed from this process was then integrated into a portable reader. The performance of the sensor was investigated and compared with the standard methods (culture and smear microscopy). It provides a good correlation (100% sensitivity and 91.7% specificity) with both methods of detection for M. tuberculosis in sputum samples henceforth, demonstrating the potential of the device as a more practical screening tool.Graphical abstract.
    Matched MeSH terms: Immunoassay/methods
  18. Kremastinou J, Polymerou V, Lavranos D, Aranda Arrufat A, Harwood J, Martínez Lorenzo MJ, et al.
    J Clin Microbiol, 2016 09;54(9):2330-6.
    PMID: 27358468 DOI: 10.1128/JCM.02544-15
    Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T. pallidum The performance of this assay was investigated previously in a multicenter study. The current study expands on that evaluation in a variety of diagnostic settings and patient populations, at seven independent laboratories. The samples included routine diagnostic samples, blood donation samples, samples from patients with confirmed HIV infections, samples from living organ or bone marrow donors, and banked samples, including samples previously confirmed as syphilis positive. This study also investigated the seroconversion sensitivity of the assay. With a total of 1,965 syphilis-negative routine diagnostic samples and 5,792 syphilis-negative samples collected from blood donations, the Elecsys Syphilis assay had specificity values of 99.85% and 99.86%, respectively. With 333 samples previously identified as syphilis positive, the sensitivity was 100% regardless of disease stage. The assay also showed 100% sensitivity and specificity with samples from 69 patients coinfected with HIV. The Elecsys Syphilis assay detected infection in the same bleed or earlier, compared with comparator assays, in a set of sequential samples from a patient with primary syphilis. In archived serial blood samples collected from 14 patients with direct diagnoses of primary syphilis, the Elecsys Syphilis assay detected T. pallidum antibodies for 3 patients for whom antibodies were not detected with the Architect Syphilis TP assay, indicating a trend for earlier detection of infection, which may have the potential to shorten the time between infection and reactive screening test results.
    Matched MeSH terms: Immunoassay/methods*
  19. Ang SH, Thevarajah TM, Woi PM, Alias YB, Khor SM
    J Chromatogr B Analyt Technol Biomed Life Sci, 2016 Mar 15;1015-1016:157-165.
    PMID: 26927875 DOI: 10.1016/j.jchromb.2016.01.059
    An immunosensor that operates based on the principles of lateral flow was developed for direct detection of hemoglobin A1c (HbA1c) in whole blood. We utilized colloidal gold-functionalized antibodies to transduce the specific signal generated when sandwich immuno-complexes were formed on the strip in the presence of HbA1c. The number and intensity of the test lines on the strips indicate normal, under control, and elevated levels of HbA1c. In addition, a linear relationship between HbA1c levels and immunosensor signal intensity was confirmed, with a dynamic range of 4-14% (20-130 mmol mol(-1)) HbA1c. Using this linear relationship, we determined the HbA1c levels in blood as a function of the signal intensity on the strips. Measurements were validated using the Bio-Rad Variant II HPLC and DCA Vantage tests. Moreover, the immunosensor was verified to be highly selective for detection of HbA1c against HbA0, glycated species of HbA0, and HbA2. The limit of detection was found to be 42.5 μg mL(-1) (1.35 mmol mol(-1)) HbA1c, which is reasonably sensitive compared to the values reported for microarray immunoassays. The shelf life of the immunosensor was estimated to be 1.4 months when stored at ambient temperature, indicating that the immunoassay is stable. Thus, the lateral flow immunosensor developed here was shown to be capable of performing selective, accurate, rapid, and stable detection of HbA1c in human blood samples.
    Matched MeSH terms: Immunoassay/methods*
  20. Seenichamy A, Bahaman AR, Mutalib AR, Khairani-Bejo S
    Biomed Res Int, 2014;2014:592858.
    PMID: 24860824 DOI: 10.1155/2014/592858
    Leptospirosis is one of the zoonotic diseases in animals and humans throughout the world. LipL21 is one of the important surface-exposed lipoproteins in leptospires and the most effective cross protective immunogenic antigen. It is widely considered as a diagnostic marker for leptospirosis. In this study, we evaluated the serodiagnostic potential of LipL21 protein of Leptospira interrogans serovar Pomona. We have successfully amplified, cloned, and expressed LipL21 in E. coli and evaluated its specificity by immunoblotting. Purified recombinant LipL21 (rLipL21) was inoculated into rabbits for the production of polyclonal antibody. Characterization of the purified IgG antibody against rLipL21 was performed by cross reactivity assay. Only sera from leptospirosis patients and rabbit hyperimmune sera recognized rLipL21 while the nonleptospirosis control sera showed no reaction in immunoblotting. We confirmed that anti-rLipL21-IgG antibody cross reacted with and detected only pathogenic leptospiral species and it did not react with nonpathogenic leptospires and other bacterial species. Results observed showed that anti-rLipL21-IgG antibody has high specificity and sensitivity to leptospires. The findings indicated that the antibody could be used in a diagnostic assay for detection of leptospires or their proteins in the early phase of infection.
    Matched MeSH terms: Immunoassay/methods
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