At the summer workshop of the Korean Endocrine Society held in 2016, some examples of protein experiments were discussed in the session entitled “All about working with proteins.” In contrast to what the title suggested, it was unrealistic to comprehensively discuss all protein analytical methods. Therefore, the goal was to outline protein experimental techniques that are useful in research or in bench work. In conversations with clinicians, however, I have always felt that researchers who do not engage in bench science have different demands than those who do. Protein research tools that are useful in bench science may not be very useful or effective in the diagnostic field. In this paper, I provide a general summary of the protein analytical methods that are used in basic scientific research, and describe how they can be applied in the diagnostic field.
Chromatography ; Education ; Immunoenzyme Techniques ; Methods* ; Molecular Imaging

In 2015, rapid human immunodeficiency virus (HIV) testing was implemented in all 25 public health centers in Seoul. During March and December 2015, 20,987 rapid HIV tests were performed, of which 116 (0.5%) were positive. Compared to those of the period before application of the rapid HIV test in place of conventional enzyme immunoassay method, the number of HIV tests performed and the number of positive results increased by sevenfold and twofold, respectively. In conclusion, expansion of the provision of rapid HIV tests in public health centers increased the number of voluntary HIV tests.
HIV* ; Humans* ; Immunoenzyme Techniques ; Korea ; Methods ; Public Health* ; Seoul*

In 2015, rapid human immunodeficiency virus (HIV) testing was implemented in all 25 public health centers in Seoul. During March and December 2015, 20,987 rapid HIV tests were performed, of which 116 (0.5%) were positive. Compared to those of the period before application of the rapid HIV test in place of conventional enzyme immunoassay method, the number of HIV tests performed and the number of positive results increased by sevenfold and twofold, respectively. In conclusion, expansion of the provision of rapid HIV tests in public health centers increased the number of voluntary HIV tests.
HIV* ; Humans* ; Immunoenzyme Techniques ; Korea ; Methods ; Public Health* ; Seoul*

OBJECTIVETo improve the key technology of immunesensors in immobilizing bio-sensitive element and keeping its bioactivity, an enzyme immunosensor based on chitosan-SiO(2) (CS-Sio(2)) hybrid membrane was fabricated. To estimate the new immunosensor Vibrio parahaemolyticus which was the main pathogens of aquatic products.

METHODSA CS-SiO(2) hybrid membrane was prepared using sol-gel method. The enzyme immunosensor was fabricated by coating the membrane and horseradish peroxidase labeled Vibrio parahaemolyticus antibody (HRP-anti-VP) on the surface of four-channel screen-printed carbon electrode. The immunosensor was characterized by cyclic voltammetry. Vibrio parahaemolyticus could be detected according to the decrease percentage (DP) of peak current before and after immune response, while cyclic voltammetry was used as an electrochemical mean to detect the products of the enzymatic reaction. Seven kinds of bacteria, like Vibrio alginolyticus, were selected for specific experiments.

RESULTSBy studying the infrared spectrum of three kinds of films, the CS-SiO(2) hybrid membrane was prepared and HRP-anti-VP was fixed in the hybrid membrane. Under the optimum conditions of immunoreaction and electrochemical detection, the DP of peak current before and after immune response showed a linear relation with lgC in the range of 10(4) - 10(9) cfu/ml, while the linear regression equation was: DP = 6.5 lgC-3.319, the correlation coefficient was 0.9958 and the detection limit was 6.9 x 10(3) cfu/ml (S/N = 3). The immunosensor possessed acceptable specificity, reproducibility (RSD < 6%), stability (the amperometric response was 95% of the initial response after a week) and accuracy (96.7% of the results obtained by the immunosensor were in agreement with those obtained by GB/T 4789.7-2003).

CONCLUSIONThe enzyme immunosensor based on CS-SiO(2) hybrid membrane gave a good performance in rapid detection of Vibrio parahaemolyticus.

Biosensing Techniques ; instrumentation ; methods ; Electrochemical Techniques ; instrumentation ; methods ; Equipment Design ; Immunoenzyme Techniques ; instrumentation ; methods ; Silicon Dioxide ; Vibrio parahaemolyticus ; isolation & purification

BACKGROUND: Although the precise pathogenesis of the Behçet's disease is not yet undertween the severity of Behçet's disease and the serum cytokine level. development of cytokine research has made it possible to find out if there is an association between the severity of Behçet's syndrome and the serum cytokine level. OBJECTIVE: Our purpose was to elucidate whether the immunopathological mechanism is associated with the serum tumor necrosis factor (TNF) and interleukin-1β (I1,1β) which are predominantly produced by monocytes/macrophages, and mterleukm-6 (IL-6). METHOD: Sixty seven patients of Behçet's disease and ten healthy adults as a control group were studied. Serum TNF and IL-6 levels were detected by enzyme immunoassay and serum IL-lβ levels by radioimmunoassay. RESULTS: There were no statistically significant differences in the serum levels of TNF, IL-1β, TL-6 compared with the control group. CONCLUSION: These data suggest that the immunopathological reactions of the Behçet's disease are not associated with a monocyte/macrophage dependent mechanism, possibly due to other immunocompetent cells.
Adult ; Humans ; Immunoenzyme Techniques ; Interleukin-6* ; Methods ; Necrosis* ; Radioimmunoassay ; Tumor Necrosis Factor-alpha

BACKGROUND: The common histopathology of Behget's disease is vasculitis associated with activation of neutrophils. The level of plasma elastase a 1 proteinase inhibitor (E a 1 PI), which represents the activation of neutrophils, may be a marker of Behcet's disease. OBJECTIVE: We examined the level of plasma elastase al proteinase inhibitor to evaluate the degree of neutrophil activation in Behcet's disease. METHOD: We measured plasma elastase a 1 proteinase inhibitor in 34 cases of untreated Behcet's disease patients and 30 cases of normal individuals by an enzyme immunoassay. We also studied the differences between the levels in two clinical types of Behcet's disease, the complete and incomplete type. RESULTS: The plasma level of elastase a 1 proteinase inhibitor was significantly higher in untreated Behcet's disease patients than in healthy controls. However, there was no significant difference between the levels in the two clinical types. CONCLUSION: These data suggest that the elevated level of plasma elastase a 1 proteinase inhibitor may reflect a state of chronic activation of neutrophils in Behcet's disease immunologically and further studies will be needed to evaluate the clinical status of Behcet's disease patients by measuring levels of plasma elastase a 1 proteinase inhibitor.
Humans ; Immunoenzyme Techniques ; Methods ; Neutrophil Activation ; Neutrophils ; Pancreatic Elastase ; Plasma* ; Vasculitis

The determination of the accurate immune status of pregnant women is crucial in order to prevent congenital toxoplasmosis. Equivocal results with conventional serological techniques are not uncommon when IgG titers are close to the cut-off value of the test, so that a confirmatory technique is needed. For this purpose, we developed a homemade immunoblot (IB) using soluble extract of Toxoplasma gondii tachyzoites and assessed it by testing 154 positive, 100 negative, and 123 equivocal sera obtained from pregnant women. In order to select the more valuable bands in terms of sensitivity and specificity, we used the Youden Index (YI). The highest YIs were those given by the 32, 36, 98, 21, and 33 bands. The simultaneous presence on the same blot of at least 3 bands showed a much higher YI (0.964) and was adapted as the positivity criterion. The analysis of results showed that our homemade IB correlated well with the commercial LDBIO Toxo II IgG(R) kit recently recommended as a confirmatory test (96.7% of concordance).
Female ; Humans ; Immunoenzyme Techniques/*methods ; Immunoglobulin G/*blood/immunology ; Pregnancy ; Reagent Kits, Diagnostic ; Toxoplasmosis/*diagnosis

BACKGROUND: Rotavirus is a major pathogen causing enteritis worldwide in children under five years of age. In recent years, immunochromatographic assay (ICA) has been widely used as a diagnostic test for rotavirus detection. This study aimed to compare and evaluate the performance of ICA-based rotavirus rapid test kits from two manufacturers. METHODS: Residual stool samples from a total of 130 children with acute enterocolitis from November 2017 to January 2018 were used. We compared the results of the two immunochromatographic methods (SD BIOLINE Rotavirus kit and GENEDIA Rotavirus Ag Rapid Test) with those of the currently used enzyme immunoassay method. RESULTS: Positive agreement, negative agreement, and total agreement rates between the SD BIOLINE rotavirus kit and the enzyme immunoassay were 98.0%, 100%, and 99.2%, respectively. Positive agreement, negative agreement, and total agreement rates between the GENEDIA Rotavirus Ag Rapid Test and the enzyme immunoassay were 96.0%, 100%, and 98.4%, respectively. CONCLUSIONS: Both rotavirus rapid test kits showed very good agreement with the conventional enzyme immunoassay. Therefore, it could be a useful test to detect rotavirus directly from stool samples in a short time.
Child ; Diagnostic Tests, Routine ; Enteritis ; Enterocolitis ; Humans ; Immunochromatography ; Immunoenzyme Techniques ; Methods ; Rotavirus

OBJECTIVESTo evaluate the correlation between signal/cutoff (S/CO) ratios of anti-HCV EIA and their true positivity for determining the predictive value of S/CO ratios.

METHODSOne hundred and fifty-nine samples of blood from donors positive for anti-HCV at the initial screening were collected from Beijing, Guangzhou, Hangzhou, Kunming and Urumchi. All the samples were retested by Ortho and 6 Chinese domestic anti-HCV EIA kits in duplicate, and detected for HCV RNA (NAT) using Chiron Procleix HIV/HCV system (transcription mediated amplification, TMA). The HCV RNA negative samples were further tested for anti-HCV by Chiron RIBA 3.0. Either NAT or RIBA positive samples were interpreted as the true positive.

RESULTSAll 7 anti-HCV EIA kits had a significant correlation between S/CO ratios and true positivity. The S/CO ratio of Ortho > or = 3.8 predicted the true positivity in 96.1% of the samples tested. The S/CO ratios of BGI-GBI, GWK, SABC, KHB, InTec, and Wantai were > or = 7.0, > or = 10.0, > or = 6.0, > or = 10.0, > or = 8.6, > or = 14.0 and predicted 96.1%, 96.1%, 97.3%, 96.0%, 96.1%, 96.0% of the true positivity, respectively.

CONCLUSIONSThe S/CO ratios of anti-HCV EIA kits are associated with the true positivity. S/CO ratios of Ortho, BGI-GBI, GWK, SABC, KHB, InTec and Wantai predicting > or = 95% true positivity are > or = 3.8, > or = 7.0, > or = 10.0, > or = 6.0, > or = 1 0.0, > or = 8.6 and > or = 14.0, respectively.

Blood Donors ; Hepacivirus ; isolation & purification ; Humans ; Immunoenzyme Techniques ; methods ; Predictive Value of Tests ; Reagent Kits, Diagnostic ; Sensitivity and Specificity

OBJECTIVETo establish the national quantity standard of hepatitis B surface antigen according to the world health organization' s standard material and prepare the national liner reference panel for hepatitis B surface antigen.

METHODSSera from hepatitis B patients and health blood donors in different areas were collected and detected by domastic HBsAg kits, anti-HBs kits, HBeAg kits, anti-HBe kits, anti-HBc kits and anti-HCV, and then confirmed by the kits produced by Abbott, which was approved by WHO. One serum with high concentration of HBsAg was calibrated with the standard sample of WHO. And then it was diluted by 1.5 fold as the liner HBsAg reference panel.

RESULTSThe HBsAg concentration of one serum was 1226 IU/ml calibrated by 21 independent standardization measurements with 7 kinds of kits. The coefficient of variation of each calibration were less then 15%. A panel contained 8 serial dilutions was established as the national liner HBsAg reference panel. The permitted range of every dilution was stipulated and the stability of the panel was detected by accelerated test.

CONCLUSIONSThe national quantity standard of hepatitis B surface antigen was established and the national quantitative reference panel for HBsAg which contains eight liner serum was developed.

China ; Hepatitis B ; virology ; Hepatitis B Surface Antigens ; blood ; Humans ; Immunoenzyme Techniques ; methods ; standards ; Reagent Kits, Diagnostic ; standards ; Reference Standards