• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.755-758
• /
• 2005

This paper describes the novel immunoassay sensing system for a portable clinical diagnosis system. It consists of a bead cage reactor and a CMOS integrated biosensor. It showed the simple and easy antibody coating method on beads by flow-through avidin biotin complex technology in a microfluidic device. It showed just 90 nL sample consumption and good result for the application of alpha feto protein. The bead cage reactor has the role of the antibody coating, antigen binding and enzyme linking for the electrochemical sensing method. The CMOS biosensor consists of ISFET (ion selective field effect transistor) biosensor and temperature sensor for detecting pH that is the byproduct of enzyme reaction. The sensitivity is 8 $kHz/^{\circ}C$ in a temperature sensor and 33 mV/pH in a pH sensor. After filling the 15 um polystyrene beads in bead cage, antibody flowed and reacted to beads. Subsequently, the biotinylated antigen flowed and bound to the antibody and GOD (glucose oxidase)-avidin conjugate flowed and reacted to the biotin of the biotinylated antigen. After this reaction process, glucose solution flowed and reacted to the GOD on beads. The hydrogen was generated by glucose-GOD reaction. And it was detected by the pH sensor.

• The Journal of Korean Society of Virology
• /
• v.28 no.4
• /
• pp.383-391
• /
• 1998

A murine monoclonal antibody (mAb) specific for the envelope glycoprotein gp120 of human immunodeficiency virus type-I (HIV -1) was chemically coupled to pokeweed antiviral protein (PAP) from Phytolacca americana. The immunotoxin was purified by FPLC using S200 colum. The purified immunotoxin efficiently bound to HIV-infected T cells as evidenced by fluorescenceactivated cell sorter analysis. The immunotoxin selectively killed human T lymphoid lines infected with $HIV-1_{IIIB}$ at less than 250 pM of the immunotoxin cells, while PAP or mAb alone did not have any significant effect on infected cells. The uninfected control T cell lines were not affected. Human cells infected with HIV-2 or other HIV-1 strains were not killed, suggesting that the killing depends completely on the antibody used for coupling. These in vitro results suggest that the PAP-mAb conjugate may be used to selectively remove cells expressing viral antigens from individuals infected with HIV.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.10
• /
• pp.1629-1637
• /
• 2007

An immunochromatography (ICG) strip test using a nanocolloidal gold-antibody probe was developed and optimized for the rapid detection of aflatoxin B1 (AFB1). A monoclonal antibody specific to AFB1 was produced from the cloned hybridoma cell (AF78), coupled with nanocolloidal gold, and distributed on the conjugate pad of the ICG strip test. The visual detection limit of the ICG strip test was 0.5 ng/ml, and this method showed a cross-reaction to aflatoxin B2, G1, and G2. In total, 172 grain and feed samples were collected and analyzed by both the ICG strip test and HPLC. The results of the ICG strip test showed a good agreement with those obtained by HPLC. These results indicated that the ICG strip test has a potential use as a rapid and cost-effective screening tool for the determination of AFB1 in real samples and could be applied to the preliminary screening of mycotoxin in food and agricultural products, generating results within 15 min without complicated steps.

• Korean Journal of Food Science and Technology
• /
• v.32 no.5
• /
• pp.1009-1014
• /
• 2000

In order to detect pantothenic acid (PA), conditions for enzyme-linked immunosorbent assay (ELISA) were established. Anti-PA-BSA antibody was produced from rabbits immunized with PA-bovine serum albumin (BSA) conjugates which were prepared by the bromoacetyl chloride [Bc] method (PA-BSA[Bc]) and by the periodate oxidation [Po] method (PA-BSA[Po]). PA-BSA[Bc] and PA-BSA[Po] was used as a coating antigen for competitive indirect(ci)ELISA. The Anti-PA-BSA[Po] antibody on ciELISA showed no competitive reaction. The detection limit of PA by ciELISA using Anti-PA-BSA[Bc] antibody was 1 ppm. The Anti-PA-BSA[Bc] antibody showed little cross-reactivity to PA derivatives such as pantoyllactone, pantetheine, pantothenyl alcohol, and acetyl CoA. The detection limit of PA by microbiological assay (MBA) was 10 ppb. Assay recoveries of PA in egg, cow's liver, and lettuce by ciELISA were 109, 64, and 344%, respectively, comparing with the MBA results.

• Korean Journal of Veterinary Research
• /
• v.32 no.4
• /
• pp.641-647
• /
• 1992

This study was conducted to determine the serum antibodies against toxoplasma in the artificially infected dogs, pet and street dogs by latex agglutination (LA) and indirect fluorescent antibody (IFA) test. LA test was carried out with commercial Toxo-MT kit (Eiken chemical Co.) and IFA test was carried out with rabbit-anti-dog IgG labelled with FITC (Cappel Co.) and toxo-antigen slides prepared in laboratory. The results obtained were as follows ; 1. Antibodies to Toxoplasma gondii in the artificially infected dogs were detected firstly at the Day 8 in IFA and Day 9 in LA test after inoculation. Positive antibody reactions by these tests were declined gradually afterward but maintained up to 12 weeks. 2. In LA test serum antibody titers in 310 test sera were shown as 10 cases(32%) in 1 : 32.5(1.0%) in 1 : 64, 4(1.3%) in 1 : 128 and 2(0.7%) in 1 : 256. In IFA test serum antibody titers 310 test sera were shown as 17 cases(5.5%) in 1 : 64, 8(2.6%) in 1 : 128 and 5(1.6%) in 1 : 256. 3. In the total of 310 sera from pet and street dogs toxoplasma antibody positive rates were 21 cases (6.8%) by LA and 30 cases (9.7%) by IFA test and the positive detection rates between these two groups by LA and IFA test were not significant(p<0.05). 4. In the total of 115 sera from pet dogs toxoplasma antibody positive rates were 12 cases(10.4%) by LA and 15(13.0%) by IFA test. And in the 195 street dogs the positive rates were 9 cases(4.6%) by LA and 15(7.7%) by IFA test. Also, the positive detection rates between these two groups by LA and IFA test were not significant(p<0.05). 5. Agreement of reactivity between LA and IFA test for 310 sera was 91.3% in total of 283 cases consisting of 12 cases(3.9%) of both LA and IFA positive and 271 cases(87.4%) of LA and IFA negative. 6. LA test was almostly equivalent to the IFA test in producibility and proved to be a simple tool for the screening of toxoplasma antibody in laboratory.

• Korean Journal of Pharmacognosy
• /
• v.11 no.3_4 s.43
• /
• pp.133-140
• /
• 1980

In order to develop the radio-immunoassay procedure for the ginsenoside $Rg_1$ we prepared the $Rg_1-BSA$ conjugate and $Rg_1-tyramine$ conjugate by condensing the $Rg_1-azide$, which was prepared by a series of six step chemical modification of the $Rg_1-side$ chain, with bovine serum albumin(BSA) or with tyramine. Rabbits were immunized by repeated injection of $Rg_1-BSA$ conjugate with Freund's Complete Adjuvant for 5 month long to obtain very potent $anti-Rg_1$ serum. The radio-labelled haptene was prepared by direct radio-iodination $(125_J)$ of $Rg_1-tyramine$ according to the chloramine-T method. The radio-immunoassay procedure was successfully furnished by using DCC method (dextran coated charcoal) and the anti-body titer of the anti-serum was found as being $1600{\sim}3200$ by using 15000cpm tracer per test. Calibration test using non-labelled $Rg_1$ showed linear competetive binding response in the $(8-300){\times}34pg$. range of non-labelled $Rg_1$. The cross reaction test using 19 ginsenoside analogues enabled us a full structure-activity analysis on the antigen-antibody reaction that the anti-body in the serum would recognize the full structure of ginsenoside $Rg_1$ except the side chain moiety.

• Korean Journal of Environmental Agriculture
• /
• v.11 no.1
• /
• pp.59-66
• /
• 1992

An enzyme immunoassay(EIA) was developed for the analysis of insecticide endosulfan and its degradation products. The sensitivity and specificity of the antibody produced were examined. Optimal conditions in the ELISA system for residue analysis were also discussed. A mixed suspension of endosulfan-hemocyanin conjugate(ES-KLH) 1.1 mg/ml and Freund's adjuvant was injected subcutaneously to white rabbits and then collected antisera were tested for titers by indirect ELISA(1/24,000). Because of difficulties in the synthesis of endosulfan peroxidase conjugate, amine derivative of endosulfan-diol was synthesized and it showed 40% of conjugate yields(2mg/ml of conjugate). the highest sensitivity obtained enzyme-conjugate was a concentration of 200ng/ml. The detection limit of endosulfan in ELISA system was 5 ppb on the standard curve. In application of ELISA for residue analysis, the recoveries were really 100% both in the spiked soil and apple sample regardless of endosulfan concentration treated. On the other hand, chlorinated hydrocarbons of similar structure with endosulfan showed low cross-reactivity$(2.2%{\sim}29.2%).$

• Korean Journal of Food Science and Technology
• /
• v.39 no.3
• /
• pp.299-303
• /
• 2007

The objective of this study was the development of immunochromatography (ICG) for the rapid and accurate detection of Listeria monocytogenes. Here, monoclonal antibodies (MAb) were conjugated with 40 nm colloidal gold particles, where the conjugate was used as the detection reagent in the ICG. The ICG was composed of three pads (sample, conjugate, and absorbance pads) and one nitrocellulose membrane. The colloidal gold-MAb conjugate was applied to the conjugate pad, and the test line and control line on the membrane were treated with MAb (FKLM-3BI2-37) and anti-mouse IgG, respectively. The detection limit of the ICG was $10^{5}$ cell/mL and it showed no cross-reaction to food borne pathogens. We inoculated meat and lettuce samples with various counts of L. monocytogenes, and analyzed them by ICG. All the inoculated meat samples gave positive results after enrichment for 24 h in LEB. These results indicate that ICG was able to serve as a primary screening tool for L. monocytogenes in various foods and agricultural products within 20 min after enrichment.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.4
• /
• pp.1154-1158
• /
• 2004

The classical ABC (avidin-biotin peroxidase complex) method for immunohistochemistry in the paraffin-embedded tissues bring into being disadvantage such as low sensitivity of antigen detection and highly background. The biotinyl-tyramide conjugation recently introduced for sensitive immunohistochemistry was applied to light microscopy in paraffin-embedded pancreatic and liver tissues. The protocol consists of an indirect method in which 4-5㎛ tissue sections are reacted successively within a specific primary antibody, followed by a biotinylated secondary antibody, streptavidin-horseradich peroxidase (HRP), and then finally with biotinyl-tyramide. The labeling obtained for insulin and collagen antigen tested in pancreatic and liver tissues, respectively, was found to be highly specific with the labeling for each antigen confined to its particular cellular compartment. In this study, fish (flounder) serum was specially applied to remove nonspecific binding. Background levels and nospecific deposition of the staining were negligible. This results suggest that super-signal induction method by biotinyl-tyramide conjugate can readily applied to antigen detection of the paraffin-embedded tissues.

• Journal of Sensor Science and Technology
• /
• v.20 no.6
• /
• pp.400-405
• /
• 2011

This study introduced the development of a strip type disposable enzyme-linked immunosensor platform for the detection of IgG. Strips of the strip sensor were fabricated by using commercial nitrocellulose filter membranes and a housing holder for the strips was manufactured by using a standard injection molding process for a plastic material. An IgG-urease conjugate was prepared and used for the competitive immune-binding with sample IgG. From the enzymatic reaction between the conjugated urease and urea added, ammonia was generated and caused a localized alkaline pH change on the immobilized antibody band which was coated onto the sensor strips. This pH increase subsequently caused a color change of the antibody band in the presence of a pH indicator, phenol red. Used in conjunction with a competitive immunoassay format, the intensity of the color produced is directly linked with the concentration of target analyte, IgG, and specific measurement of IgG in a lateral flow immunoassay format was achieved over the range 100 ppb to 2000 ppb IgG.