scholarly journals Efficient detection of pre-proinsulin by double antibody sandwich ELISA

2020 ◽  
Author(s):  
Zhu Zhu ◽  
Guoliang Ma ◽  
Li Wang ◽  
Han Wang ◽  
Hengfang Tang ◽  
...  

Abstract ObjectiveTo generate monoclonal antibodies against pre-proinsulin (PPI), and establish sandwich ELISA method to provide a basis for PPI detection in recombinant human insulin production.MethodsThe Balb /c mice were immunized with PPI, and the hybridomas secreting anti-PPI monoclonal antibodies were obtained by conventional cell fusion technique and ELISA screening.The antibody was purified using a Protein G gel column and identified for purity by SDS-PAGE. Pairing effect was found by the sandwich ELISA, and the specificity of the paired antibody was determined. A paired antibody with better specificity was selected to establish sandwich ELISA, and construct a quantitative curve, the accuracy and sensitivity of the method were evaluated.ResultsSix anti-PPI monoclonal antibodies were obtained, named P1, P2, P3, P4, P5 and P6, of which P5 had the highest titer. The sandwich ELISA method was established with P5 for plating and P2 for detection antibodie. The linear range of the quantitative curve of PPI by sandwich ELISA was 0. 645-82.5 pg/mL, the recovery was 89%–95%, and the limit of detection was 3.06 pg/mL.ConclusionSix monoclonal antibodies against PPI were generated and the sandwich ELISA method was established to detect PPI in process control and product release control for recombinant human insulin production.

1996 ◽  
Vol 59 (11) ◽  
pp. 1158-1163 ◽  
Author(s):  
HUAIZE TIAN ◽  
TAKAHISA MIYAMOTO ◽  
TAKASHI OKABE ◽  
YOICHIRO KURAMITSU ◽  
KEN-ICHI HONJOH ◽  
...  

A rapid-detection method was developed for food-borne dulcitol-positive Salmonella spp. in foods that involves a new preenrichment and selective enrichment system and a sandwich ELISA using two monoclonal antibodies against dulcitol 1-phosphate dehydrogenase. Preenrichment and selective enrichment were in Enterobacteriaceae enrichment mannitol (EEM) broth at 42°C for 6 h and in a new dulcitol-magnesium chloride-pyridinesulfonic acid brilliant green-novobiocin (DMPBN) medium at 42°C for 27 h, respectively. The cells were collected from the selective enrichment culture and suspended in 0.1 ml of 1 N NaOH for 2 min. The solution was neutralized with 0.1 ml of 2 M Tris-HCl buffer (pH 7.5) and the mixture was used as a sample for ELISA. The detection sensitivity of the ELISA was 105 CFU of Salmonella spp. per ml of culture. Competing non-Salmonella organisms in raw food did not interfere with the detection of Salmonella cells even when present at 107: 1 (non-Salmonella: Salmonella ratio) in food. Nonmotile Salmonella gallinarum was detected by the ELISA. The minimum detectable number of initial inoculum of Salmonella typhimurium was 0.69 CFU/25 g of raw chicken after the preenrichment in EEM broth and the selective enrichment in DMPBN medium. The present ELISA method required a total analysis time of 36 h including the preenrichment and selective enrichment periods. The ELISA method was compared with a conventional cultural method for the detection of Salmonella cells in 130 samples of raw foods. Of the samples tested, 16 were Salmonella-positive and 114 samples were negative by both methods. False-positive and false-negative results were not encountered.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nils Müller ◽  
Juan Pablo Robles ◽  
Magdalena Zamora ◽  
Johannes Ebnet ◽  
Hülya Markl-Hahn ◽  
...  

Vasoinhibin is a protein hormone with antiangiogenic, antivasodilatatory, and antivasopermeability effects generated by the proteolytic cleavage of prolactin. The discovery of its role in diabetic retinopathy and peripartum cardiomyopathy led to the evaluation of new pharmacological treatments in clinical interventional trials. However, the quantitative evaluation of vasoinhibin in biological samples from patients has not been possible due to the lack of vasoinhibin-specific antibodies. Recently, loop 1 of vasoinhibin was identified to have a different three-dimensional structure compared to PRL, and thus to contain vasoinhibin-specific epitopes. Here, we report the development of two sets of vasoinhibin-specific monoclonal antibodies against two neighboring regions of the vasoinhibin loop 1. An experimental sandwich ELISA with two monoclonal anti-vasoinhibin antibodies was developed, which had no cross-reactivity to recombinant human full-length prolactin. The ELISA had a quantitation limit of 100 ng/ml, and intra-assay- and inter-assay coefficients of variation of 12.5% and 14%, respectively. The evaluation of 15 human serum samples demonstrated concentrations of below limit of detection (n=3), below limit of quantitation (n=1) and between 0.23 µg/ml (230 ng/ml) to 605 µg/ml (n=12) in the quantifiable range. Despite the high specificity of the monoclonal-monoclonal antibody sandwiches which discriminate vasoinhibin from PRL, there might be cross-reactivities by serum proteins other than vasoinhibin. A fully established vasoinhibin ELISA may support diagnostic and therapeutic measures in vascular diseases.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2000-2000 ◽  
Author(s):  
Tara L Arvedson ◽  
George Doellgast ◽  
Hossein Salimi-Moosavi ◽  
Chadwick King ◽  
Ian Foltz ◽  
...  

Abstract Abstract 2000 Poster Board I-1022 Hepcidin is a 25 amino acid peptide that is the central mediator of iron metabolism. Iron excess, deficiency and maldistribution have been implicated in the etiology of many diseases including atherosclerosis, diabetes, neurodegeneration and the anemia of inflammation. Determination of hepcidin levels may be useful in diagnosis and treatment decisions for some or all of these diseases. Serum hepcidin measurement has so far been limited to a prohepcidin (60 amino acid hepcidin precursor) ELISA, mass spectrometry (MS)-based assays or competition ELISAs using polyclonal anti-hepcidin antibodies. The current work describes the generation of a sandwich ELISA using monoclonal antibodies to detect human hepcidin (hHepc) and optimization of assay conditions to resolve inconsistencies between MS- and ELISA-based detection. The ability of two anti-hHepc antibodies to sandwich (bind simultaneously) with hHepc was demonstrated using a rabbit polyclonal antibody preparation from hHepc-immunized animals. The same polyclonal antibody preparation was used for both hHepc capture and detection. The limit of detection achieved with this assay was O.D.450<1, suggesting that only a small proportion of the total antibodies could bind concurrently. To improve hHepc detection, a panel of monoclonal antibodies was screened for the ability to sandwich. Antibody epitope characterization studies using purified antibodies and >1000 hybridoma supernatants identified three classes of antibodies: classes 1 and 2 each recognized epitopes found in both full length mature hHepc (hHepc 25) and a shorter version (hHepc 20); class 3 bound a different epitope and demonstrated an increased affinity for hHepc 25 over hHepc 20. The majority of antibodies characterized were in class 1 while antibodies in classes 2 and 3 were rare (∼1% of antibody panel) highlighting the difficulty in achieving a sandwiching event. Antibodies 19D12 (class 1) and 23F11 (class 2) were identified as the optimal sandwich pair with a detection range of approximately 0.2-1000 ng/ml using synthetic hHepc. Initial comparisons of data generated using the sandwich ELISA and a fully-quantitative MS-based assay demonstrated a lack of consistent agreement. This issue was somewhat addressed by introduction of an alkaline treatment step to dissociate any protein/hHepc complexes in serum. Subsequent comparison of the two assays using sera from several different patient populations (anemia of cancer, chemotherapy-induced anemia, kidney disease) as well as healthy donors demonstrated good correlation (R2 range = 0.83-0.92; n=237). This sandwich ELISA may represent a tool for aligning the MS and ELISA-generated results in a format that has the potential to be high throughput and widely available. Disclosures: Arvedson: Amgen: Employment. Doellgast:Amgen: Employment. Salimi-Moosavi:Amgen: Employment. King:Amgen: Employment. Foltz:Amgen: Employment. Chen:Amgen: Employment. Li:Amgen: Employment. Sasu:Amgen: Employment.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Yi Ma ◽  
Chao Ni ◽  
Emmanuel E. Dzakah ◽  
Haiying Wang ◽  
Keren Kang ◽  
...  

Human immunodeficiency virus type 1 (HIV-1) p24 protein is the most abundant viral protein of HIV-1. This protein is secreted in blood serum at high levels during the early stages of HIV-1 infection, making it a biomarker for early diagnosis. In this study, a colloidal gold immunochromatographic assay (GICA) was established for detecting p24 protein using mouse monoclonal antibodies (mAbs). The HIV-1 p24 protein was expressed inE. colistrain BL21 and the purified protein was used to immunize mice. Stable hybridoma cell lines secreting anti-p24 monoclonal antibodies were obtained after ELISA screening and subcloning by limiting dilution. 34 different capture and labeling mAb pairs were selected by a novel antibody-capture indirect sandwich ELISA and then applied in GICA to detect p24 protein. The GICA method has a limit of detection (LOD) of 25 pg/mL and could detect p24 protein in all 10 positive samples obtained from the National Reference of HIV-1 p24 antigen. Out of 153 negative samples tested, 3 false positives results were obtained. The overall specificity of this test was 98.03%. The good sensitivity and specificity of this method make it a suitable alternative to provide a more convenient and efficient tool for early diagnosis of HIV infection.


1987 ◽  
Vol 61 (3) ◽  
pp. 196-202 ◽  
Author(s):  
C. Aguila ◽  
C. Cuéllar ◽  
S. Fenoy ◽  
J. L. Guillén

ABSTRACTA sandwich ELISA method using previously described E/S antigen-specific monoclonal antibodies has been developed to detect circulating immune complexes in patients infected with Toxocara canis. This technique could be used for the study of the dynamics of the parasite-host relationship, as we believe the detection of immune complexes and/or soluble antigen to be an improvement over detection of antibodies only. In this parasitosis, antibodies may be present in residual levels for prolonged periods after active infection.


Toxins ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 533 ◽  
Author(s):  
Takeshi Tsumuraya ◽  
Masahiro Hirama

“Ciguatera” fish poisoning (CFP) is one of the well-known food poisoning caused by the ingestion of fish that have accumulated trace amounts of ciguatoxins (CTXs). CFP affects more than 50,000 individuals annually. The difficulty in preventing CFP comes from the lack of reliable methods for analysis of CTXs in contaminated fish, together with the normal appearance, taste, and smell of CTX-contaminated fish. Thus, a sensitive, accurate, routine, and portable analytical method to detect CTXs is urgently required. Monoclonal antibodies (mAbs) specific against either wing of major CTX congeners (CTX1B, 54-deoxyCTX1B, CTX3C, and 51-hydroxyCTX3C) were generated by immunizing mice with rationally designed synthetic haptens-KLH conjugates instead of the CTXs. Haptenic groups with a surface area greater than 400 Å2 are required to produce mAbs that can strongly bind to CTXs. Furthermore, a highly sensitive fluorescence-based sandwich enzyme-linked immunosorbent assay (ELISA) was developed. This protocol can detect and quantify four major CTX congeners (CTX1B, 54-deoxyCTX1B, CTX3C, and 51-hydroxyCTX3C) with a limit of detection (LOD) of less than 1 pg/mL. The LOD determined for this sandwich ELISA is sufficient to detect CTX1B-contaminated fish at the FDA guidance level of 0.01 ppb.


Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 333
Author(s):  
Renjian Hu ◽  
Zhen Dong ◽  
Kui Zhang ◽  
Guangzhao Pan ◽  
Chongyang Li ◽  
...  

At present, the clinical detection method of human papillomavirus (HPV) is mainly based on the PCR method. However, this method can only be used to detect HPV DNA and HPV types, and cannot be used to accurately predict cervical cancer. HPV16 E7 is an oncoprotein selectively expressed in cervical cancers. In this study, we prepared an HPV16 E7-histidine (HIS) fusion oncoprotein by using a prokaryotic expression and gained several mouse anti-HPV16 E7-HIS fusion oncoprotein monoclonal antibodies (mAbs) by using hybridoma technology. Two mAbs, 69E2 (IgG2a) and 79A11 (IgM), were identified. Immunocytochemistry, immunofluorescence, immunohistochemistry, and Western blot were used to characterize the specificity of these mAbs. The sequences of the nucleotide bases and predicted amino acids of the 69E2 and 79A11 antibodies showed that they were novel antibodies. Indirect enzyme-linked immunosorbent assay (ELISA) with overlapping peptides, indirect competitive ELISA, and 3D structural modeling showed that mAbs 69E2 and 79A11 specifically bound to the three exposed peptides of the HPV16 E7 (HPV16 E749–66, HPV16 E773–85, and HPV16 E791–97). We used these two antibodies (79A11 as a capture antibody and 69E2 as a detection antibody) to establish a double-antibody sandwich ELISA based on a horseradish peroxidase (HRP)-labeled mAb and tetramethylbenzidine (TMB) detection system for quantitative detection of the HPV16 E7-HIS fusion oncoprotein, however, it was not ideal. Then we established a chemiluminescence immunoassay based on a labeled streptavidin-biotin (LSAB)-ELISA method and luminol detection system—this was sufficient for quantitative detection of the HPV16 E7-HIS fusion oncogenic protein in ng levels and was suitable for the detection of HPV16-positive cervical carcinoma tissues. Collectively, we obtained two novel mouse anti-HPV16 E7 oncoprotein mAbs and established an LSAB-lumino-dual-antibody sandwich ELISA method for the detection of the HPV16 E7-HIS fusion oncogenic protein, which might be a promising method for the diagnosis of HPV16-type cervical cancers in the early stage.


2014 ◽  
Vol 41 (1) ◽  
pp. 22-29 ◽  
Author(s):  
V. Manolov ◽  
B. Atanasova ◽  
V. Vasilev ◽  
K. Tzatchev ◽  
M. Velizarova

Summary Hepcidin is a 25-aminoacid cysteine-rich iron regulating peptide. Hepcidin quantification in human blood may provide further insights for the pathogenesis of disorders of iron homeostasis and might prove a valuable tool for clinicians for the differential diagnosis of anaemia. This study describes ELISA immunoassay for hepcidin quantification in human serum. We used a sandwich ELISA method from USCN Life Science inc., that consists of ready to use, pre-coated 96-well strip plate with 2 antihepcidin-25 monoclonal antibodies. A recombinant hepcidin in 16 μg/l concentration is used as a standard; it reconstitutes with 1.0 ml standard diluent to prepare a stock solution. We correlated ELISA results of hepcidin-25 measurements in healthy population with hemodialysis patients. The sandwich ELISA was highly specific for hepcidin-25, having a low limit of quantification of 0.020 μg/l. Hepcidin- 25 concentrations were increased in hemodialysis patients (median 33.05 μg/l, range 22.31 -60.98 μg/l, n = 10) compared with healthy individuals (median 12.41 μg/l, range 6.05-18.53 μg/l, n = 40). The use of 2 monoclonal antibodies in a sandwich ELISA format provides a robust, convenient and not very expensive method for measuring concentrations of the active form of hepcidin. It should help to improve our understanding of the role of hepcidin in regulating iron metabolism.


1995 ◽  
Vol 58 (8) ◽  
pp. 847-852 ◽  
Author(s):  
TAKAHISA MIYAMOTO ◽  
HUAIZE TIAN ◽  
KIYOSHI MATSUNO ◽  
RYOJI TAKATA ◽  
SHOJI HATANO

Monoclonal antibodies raised against dulcitol 1-phosphate dehydrogenase of Salmonella typhimurium IFO 12529 were screened against 20 serotypes of Salmonella and 13 non-Salmonella bacteria. A sandwich-capture, enzyme-linked immunosorbent assay (sandwich ELISA) was developed for detection of Salmonella in food. The assay utilizes two monoclonal antibodies (DUI2 and DU28) which show no cross-reactions with non-Salmonella bacteria. The limit of detection of the sandwich ELISA was about 1 × 107 CPU/ml. After cultivation in a medium containing dulcitol at 37°C for 18 h followed by the sandwich ELISA. 1 CPU of Salmonella was detected. Although a high inoculum level of E. coli interfered with the detection of Salmonella, the interference was minimized by using a selective dulcitol-magnesium chloride-pyridinesulfonic acid medium for enrichment. The novel ELISA procedure detected Salmonella in chicken filtrates inoculated with 1.4 CPU/50 m1 and 1.3 × 107 CPU/50 ml of E. coli within 25 h.


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