scholarly journals Streptavidin-conjugated gold nanoclusters as ultrasensitive fluorescent sensors for early diagnosis of HIV infection

2018 ◽  
Vol 4 (11) ◽  
pp. eaar6280 ◽  
Author(s):  
Aditya Dileep Kurdekar ◽  
L. A. Avinash Chunduri ◽  
C. Sai Manohar ◽  
Mohan Kumar Haleyurgirisetty ◽  
Indira K. Hewlett ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Limit Of Detection ◽  
Gold Nanoclusters ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Metal Nanoclusters ◽  
Detection Range ◽  
In Silico Studies ◽  
P24 Antigen ◽  
Hiv 1

We have engineered streptavidin-labeled fluorescent gold nanoclusters to develop a gold nanocluster immunoassay (GNCIA) for the early and sensitive detection of HIV infection. We performed computational simulations on the mechanism of interaction between the nanoclusters and the streptavidin protein via in silico studies and showed that gold nanoclusters enhance the binding to the protein, by enhancing interaction between the Au atoms and the specific active site residues, compared to other metal nanoclusters. We also evaluated the role of glutathione conjugation in binding to gold nanoclusters with streptavidin. As proof of concept, GNCIA achieved a sensitivity limit of detection of HIV-1 p24 antigen in clinical specimens of 5 pg/ml, with a detection range up to1000 pg/ml in a linear dose-dependent manner. GNCIA demonstrated a threefold higher sensitivity and specificity compared to enzyme-linked immunosorbent assay for the detection of HIV p24 antigen. The specificity of the immunoassay was 100% when tested with plasma samples negative for HIV-1 p24 antigen and positive for viruses such as hepatitis B virus, hepatitis C virus, and dengue. GNCIA could be developed into a universal labeling technology using the relevant capture and detector antibodies for the specific detection of antigens of various pathogens in the future.

scholarly journals An Electrochemical Sensor Based on Gold-Nanocluster-Modified Graphene Screen-Printed Electrodes for the Detection of β-Lactoglobulin in Milk

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3956
Author(s):  
Jingyi Hong ◽  
Yuxian Wang ◽  
Liying Zhu ◽  
Ling Jiang
Keyword(s):  
Electrochemical Sensor ◽  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
Gold Nanoclusters ◽  
Enzyme Linked Immunosorbent Assay ◽  
Gold Nanocluster ◽  
Detection Range ◽  
Screen Printed Electrodes ◽  
Β Lactoglobulin ◽  
Screen Printed

A simple and low-cost electrochemical sensor based on multimodified screen-printed electrodes (SPEs) was successfully synthesized for the sensitive detection of β-lactoglobulin (β-Lg). The surface treatment of SPEs was accomplished by a simple drip coating method using polyethyleneimine (PEI), reduced graphene oxide (rGO), and gold nanoclusters (AuNCs), and the treated SPEs showed excellent electrical conductivity. The modified SPEs were then characterized with UV-Vis, SEM, TEM, and FTIR to analyze the morphology and composition of the AuNCs and the rGO. An anti-β-Lg antibody was then immobilized on the composite material obtained by modifying rGO with PEI and AuNCs (PEI-rGO-AuNCs), leading to the remarkable reduction in conductivity of the SPEs due to the reaction between antigen and antibody. The sensor obtained using this novel approach enabled a limit of detection (LOD) of 0.08 ng/mL and a detection range from 0.01 to 100 ng/mL for β-Lg. Furthermore, pure milk samples from four milk brands were measured using electrochemical sensors, and the results were in excellent agreement with those from commercial enzyme-linked immunosorbent assay (ELISA) methods.

SENSITIVITY, SPECIFICITY, AND PREDICTIVE VALUE OF PHYSICAL EXAMINATION, CULTURE, AND OTHER LABORATORY STUDIES IN THE DIAGNOSIS DURING EARLY INFANCY OF VERTICALLY ACQUIRED HUMAN IMMUNODEFICIENCY VIRUS INFECTION

PEDIATRICS ◽  
1994 ◽  
Vol 94 (2) ◽  
pp. 274-275
Author(s):  
Susan E. Pacheco ◽  
William T. Shearer
Keyword(s):  
Clinical Trials ◽  
Physical Examination ◽  
Hiv Infection ◽  
Laboratory Studies ◽  
Diagnostic Laboratory ◽  
Predictive Values ◽  
P24 Antigen ◽  
Aids Clinical Trials ◽  
Sensitivity Specificity ◽  
Hiv 1

Purpose of the Study. To determine the HIV vertical transmission rate in an unselected group of infants born to HIV-infected mothers, and to examine the sensitivity, specificity, and positive and negative predictive values of physical examination and diagnostic laboratory studies (HIV culture, serum quantitative immunoglobulins and HIV-1 p24 antigen) in the diagnosis of HIV infection. Study Population. A group of 142 infants referred solely because they were born to HIV-infected mothers were selected for this study. Methods. Epidemiological and clinical data were obtained retrospectively from the Baylor Pediatric AIDS Clinical Trials Group HIV Infection Registry and medical records. The information recorded included results of physical examination and diagnostic laboratory tests (HIV culture, serum quantitative immunoglobulins, and HIV-1 p24 antigen). HIV cultures were performed according to a consensus protocol developed for the National Institute of Allergy and Infectious Diseases AIDS Clinical Trials Group. Results. Of 142 infants whose HIV infection status was known at the time of the study, 17 (20%) had confirmed infection, and 68 (80%) had seroreverted with no evidence of infection. All HIV-infected infants were at least 3 months old when abnormal physical exam findings became apparent (lymphadenopathy and hepatosplenomegaly), but similar findings were noted in an equal number of HIV-uninfected infants. All infected infants available were HIV culture positive by 6 months of age (16/16). There was no positive cultures reported in the infants who seroreverted (32/32). Elevated immunoglobulins (IgG, IgA, IgM) were present by 6 months of age in a high percentage of infected infants. Nearly one-half of the uninfected infants had elevated immunoglobulin levels during the first 6 months of life, but in 50% of the cases it was IgG alone.

scholarly journals Hyperbaric hyperoxia exposure in suppressing human immunodeficiencyvirus replication: An experimental in vitro in peripheral mononuclear blood cells culture

2020 ◽  
Author(s):  
Retno Budiarti ◽  
Siti Qamariyah Khairunisa ◽  
Nasronudin ◽  
Kuntaman ◽  
Guritno
Keyword(s):  
Hiv Infection ◽  
Healthy Volunteers ◽  
Hyperbaric Oxygen ◽  
Experimental Unit ◽  
Control Group ◽  
P24 Antigen ◽  
Hyperbaric Exposure ◽  
Interferon Α2 ◽  
Hiv 1

Cellular immune has an important role in response HIV infection, which is attack the infected cells to activate signaling molecule. Hyperbaric Oxygen (HBO) worked as complementary treatment for HIV infection. The production of ROS and RNS molecules during hyperbaric exposure can affect gene expression which contributes to cellular adaptative response. This study was conducted to explore the mechanisms of cellular adaptive response to HIV infection during hyperbaric exposure. This study was carried on in vitro using healthy volunteers’ PBMCs (Peripheral Blood Mononuclear Cells) cultures infected with HIV-1. The study was conducted as a post- test only group design. The experimental unit was PBMC from venous blood of healthy volunteers which were cultured in vitro and infected by co-culturing with HIV-1 in MT4 cell line. The experimental unit consist of treatment and control group. Each group examined the expression of transcription factor NFκB, Interferon α, reverse transcriptase inhibitors (p21), and the amount of HIV-1 p24 antigen. There were increasingly significant differences in the expression of the trancription factor of NFκB, p21, and HIV-1 p24 antigen,as well as mRNA transcription of interferon α2 between treatment and controlgroup. By decreasing p24 antigen showed that HBO exposure was able to suppress HIV-1 replication. The exposure to hyperbaric oxygen at the pressure of 2.4 ATAand 98% oxygen wasable to produce ROS and RNS molecules, which play a role in cellular adaptive responses through increasing the expression of nfĸb, p21 and mRNA of interferon α2 plays a role in inhibition mechanism of HIV-1 replication in cells.

scholarly journals Adaptation of ELISA Detection of Plasmodium Falciparum and Plasmodium Vivax Circumsporozoite Proteins in Mosquitoes to a Multiplex Bead-Based Immunoassay

2021 ◽  
Author(s):  
Alice Sutcliffe ◽  
Seth R. Irish ◽  
Eric Rogier ◽  
Micaela Finney ◽  
Sarah Zohdy ◽  
...  
Keyword(s):  
Lower Limit ◽  
Limit Of Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Limits Of Detection ◽  
Detection Range ◽  
Cutoff Value ◽  
Sporozoite Rate ◽  
The Impact ◽  
Lower Limits ◽  
Multiplex Bead

Abstract Background: Plasmodium spp. sporozoite rates in mosquitoes are used to better understand malaria transmission intensity, the relative importance of vector species and the impact of interventions. These rates are typically estimated using an enzyme-linked immunosorbent assay (ELISA) utilizing antibodies against the circumsporozoite protein of P. falciparum (Pf), P. vivax VK210 (Pv210) or P. vivax VK247 (Pv247), employing assays that were developed over three decades ago. The ELISA method requires a separate assay plate for each analyte tested and can be time consuming as well as requiring sample volumes not always available. The bead-based multiplex platform allows simultaneous measurement of multiple analytes and may improve the lower limit of detection for sporozoites.Methods: Recombinant positive controls for Pf, Pv210 and Pv247 and previously developed circumsporozoite (cs) ELISA antibodies were used to optimize conditions for the circumsporozoite multiplex bead assay (csMBA) and to determine the detection range of the csMBA. After optimizing assay conditions, known amounts of sporozoites were used to determine the lower limit of detection for the csELISA and csMBA and alternate cutoff measures were applied to demonstrate how cutoff criteria can impact lower limits of detection. Sporozoite rates from 1275 mosquitoes collected in Madagascar and 255 mosquitoes collected in Guinea were estimated and compared using the established csELISA and newly optimized csMBA. All mosquitoes were tested (initial test), and those that were positive were retested (retest). When sufficient sample volume remained, an aliquot of homogenate was boiled and retested (boiled retest), to denature any heat-unstable cross-reactive proteins. Results: Following optimization of the csMBA, the lower limit of detection was 25 sporozoites per mosquito equivalent for Pf, Pv and Pv247 whereas the lower limits of detection for csELISA were found to be 1400 sporozoites for Pf, 425 for Pv210 and 1650 for Pv247. Combined sporozoite rates after re-testing of samples that initially tested positive for Madagascar mosquitoes by csELISA and csMBA were 1.4% and 10.3%, respectively, and for Guinea mosquitoes 2% by both assays. Boiling of samples followed by csMBA resulted in a decreased in the Madagascar sporozoite rate to 2.8-4.4% while the Guinea csMBA sporozoite rate remained at 2.0%. Using an alternative csMBA cutoff value of median fluorescence intensity (MFI) of 100 yielded a sporozoite rate after confirmational testing of 3.7% for Madagascar samples and 2.0% for Guinea samples. Whether using csMBA or csELISA, the following steps may help minimize false positives: specimens are appropriately stored and bisected anterior to the thorax-abdomen junction, aliquots of homogenate are boiled and retested following initial testing, and an appropriate cutoff value is determined.Conclusions: The csMBA is a cost-comparable and time saving alternative to the csELISA and may help eliminate false negatives due to a lower limit of detection, thus increasing sensitivity over the csELISA. The csMBA expands the potential analyses that can be done with a small volume of sample by allowing multiplex testing where analytes in addition to Pf, Pv210 and Pv247 can be added following optimization.

scholarly journals Development of a Direct Competitive ELISA Kit for Detecting Deoxynivalenol Contamination in Wheat

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 50
Author(s):  
Li Han ◽  
Yue-Tao Li ◽  
Jin-Qing Jiang ◽  
Ren-Feng Li ◽  
Guo-Ying Fan ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
High Performance ◽  
Limit Of Detection ◽  
High Specificity ◽  
Hplc Method ◽  
Rapid Screening ◽  
Enzyme Linked Immunosorbent Assay ◽  
Detection Range ◽  
Technical Requirements ◽  
Relative Standard

This study was conducted to develop a self-assembled direct competitive enzyme-linked immunosorbent assay (dcELISA) kit for the detection of deoxynivalenol (DON) in food and feed grains. Based on the preparation of anti-DON monoclonal antibodies, we established a standard curve with dcELISA and optimized the detection conditions. The performance of the kit was evaluated by comparison with high-performance liquid chromatography (HPLC). The minimum detection limit of DON with the kit was 0.62 ng/mL, the linear range was from 1.0 to 113.24 ng/mL and the half-maximal inhibition concentration (IC50) was 6.61 ng/mL in the working buffer; there was a limit of detection (LOD) of 62 ng/g, and the detection range was from 100 to 11324 ng/g in authentic agricultural samples. We examined four samples of wheat bran, wheat flour, corn flour and corn for DON recovery. The average recovery was in the range of 77.1% to 107.0%, and the relative standard deviation (RSD) ranged from 4.2% to 11.9%. In addition, the kit has the advantages of high specificity, good stability, a long effective life and negligible sample matrix interference. Finally, wheat samples from farms in the six provinces of Henan, Anhui, Hebei, Shandong, Jiangsu and Gansu in China were analyzed by the kit. A total of 30 samples were randomly checked (five samples in each province), and the results were in good agreement with the standardized HPLC method. These tests showed that the dcELISA kit had good performance and met relevant technical requirements, and it had the characteristics of accuracy, reliability, convenience and high-throughput screening for DON detection. Therefore, the developed kit is suitable for rapid screening of DON in marketed products.

Early detection of HIV-1 in men from Kenya using a synthetic peptide and a p24 antigen enzyme-linked immunosorbent assay

AIDS ◽  
1994 ◽  
Vol 8 (11) ◽  
pp. 1625 ◽  
Author(s):  
M. W. Tyndall ◽  
A. M. Gomez ◽  
G. Maitha ◽  
J. O. Ndinya-Achola ◽  
I. MacLean ◽  
...  
Keyword(s):  
Early Detection ◽  
Immunosorbent Assay ◽  
Synthetic Peptide ◽  
Enzyme Linked Immunosorbent Assay ◽  
P24 Antigen ◽  
Hiv 1

scholarly journals Contemporary diagnosis of HIV infection in pediatrician’s practice

2020 ◽  
Vol 11 (3) ◽  
pp. 73-80
Author(s):  
Jean-Claude Hakizimana ◽  
Dmitry O. Ivanov ◽  
Elena B. Yastrebova ◽  
Ruslan A. Nasyrov ◽  
Denis A. Gusev ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Laboratory Diagnostics ◽  
Primary Diagnostics ◽  
Study Evaluation ◽  
P24 Antigen ◽  
Return Visits ◽  
The Cost ◽  
And Control ◽  
Late Detection ◽  
Hiv 1

The objective of the study: evaluation of the effectiveness of clinico-epidemiological and laboratory diagnostics of HIV infection in pediatric practice. Materials and methods. Under the supervision of pediatricians of the Department of motherhood and childhood of the St. Petersburg AIDS Center, there were 388 HIV-infected children aged from one month to 17 years inclusive. Due to the reasons of late detection and HIV dissidence of parents, 18 children (4%) died cumulatively among the children observed in St. Petersburg center for AIDS. The object of the immunohistochemical study was randomly selected HIV-infected children who applied to the center for prevention and control of AIDS for return visits. Material for testing for the presence of HIV-1 P24 antigen was taken from the back wall of the nasopharynx. Results. When analyzing the ways of HIV infection in children registered at the maternity and childhood Department of the Saint Petersburg AIDS Center, it turned out that 363 children were infected perinatally (93,6%), 23 (5,9%) sexually infected and 2 children through injecting drugs (0.5%). The proposed method of immunocytochemistry for the diagnosis of HIV infection in children can find its application, especially for primary diagnostics, which may simplify and reduce the cost of laboratory diagnostics.

scholarly journals Ultrasensitive ELISA Developed for Diagnosis

2019 ◽  
Author(s):  
Kanako Iha ◽  
Mikio Inada ◽  
Naoki Kawada ◽  
Kazunari Nakaishi ◽  
Satoshi Watabe ◽  
...  
Keyword(s):  
Detection Method ◽  
De Novo ◽  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Nucleic Acid Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Medical Facilities ◽  
Ultrasensitive Assay ◽  
Maximum Absorption Wavelength ◽  
Hiv 1

For the diagnosis of disease, the ability to quantitatively detect trace amounts of the causal proteins from bacteria/viruses as biomarkers in patient specimens is highly desirable. Here we introduce a simple, rapid, and colorimetric assay as a de novo, ultrasensitive detection method. This ultrasensitive assay consists of sandwich enzyme-linked immunosorbent assay (ELISA) and thionicotinamide-adenine dinucleotide (thio-NAD) cycling, forming an ultrasensitive ELISA, in which the signal substrate (i.e., thio-NADH) accumulates in a triangular manner, and the accumulated thio-NADH is measured at its maximum absorption wavelength of 400 nm. We have successfully achieved a limit of detection of ca. 10–18 moles/assay for a target protein. As an example of infectious disease detection, HIV-1 p24 could be measured at 0.0065 IU/assay (i.e., 10−18 moles/assay), and as a marker for a lifestyle-related disease, adiponectin could be detected at 2.3 × 10−19 moles/assay. In particular, despite the long-held belief that the trace amounts of adiponectin in urine can only be detected using a radioisotope, our ultrasensitive ELISA was able to detect urinary adiponectin. This method is highly versatile, because simply changing the antibody enables the detection of various proteins. This assay system requires only the measurement of absorbance, thus it requires equipment that is easily obtained by medical facilities, which facilitates diagnosis in hospitals and clinics. Moreover, we describe an expansion of our ultrasensitive ELISA to a non-amplification nucleic acid detection method for nucleic acids using hybridization. These de novo methods will enable simple, rapid, and accurate diagnosis.

Immunocytochemical identification of HIV (p24) antigen in parotid lymphoid lesions

1989 ◽  
Vol 103 (11) ◽  
pp. 1063-1066 ◽  
Author(s):  
J. M. Bruner ◽  
K. R. Cleary ◽  
F. B. Smith ◽  
J. G. Batsakis
Keyword(s):  
Human Immunodeficiency Virus ◽  
Hiv Infection ◽  
Lymphoid Cells ◽  
Gag Protein ◽  
Laboratory Markers ◽  
Immunodeficiency Virus ◽  
Lymphoepithelial Cysts ◽  
Patients At Risk ◽  
P24 Antigen ◽  
Hiv 1

AbstractAntibodies to specific human immunodeficiency virus (HIV) polypeptides are important laboratory markers of HIV infection. We have used an antibody to the major structural gag protein p24 of HIV-1 virus to immunochemically localize this capsid antigen in lymphoid cells from seven of eight patients at risk for HIV infection and who presented with parotid lymphadenopathy and lymphoepithelial cysts of the parotid gland. A clinicopathological assessment of these two manifestations as they relate to HIV infection is also presented.

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