Current diagnosis of human immunodeficiency virus (HIV) infection relies on the detection of anti-HIV antibodies by enzyme-linked immunosorbent assay (ELISA). Recently, kits detecting both p24 antigenemia and anti-HIV/anti-HIV2 antibodies have been developed. Thus, it is necessary to compare those kits developed as such. The aim of this study was to evaluate the diagnostic efficiency of a simultaneous detection test of p24 antigen and anti-HIV1/2 antibodies in a low prevalence area. Eight hundred and four randomly selected sera proven negative for HIV infection and 110 sera from 54 patients diagnosed as HIV infected, obtained between 1999 and 2000, were used for this study. One commercial lot of panels composed of consecutive sera obtained from known HIV-infected patient was included. Anti-HIV1/2 antibodies were detected by two different commercial ELISA kits, one from Korean and the other from German manufacturer. P24 antigen test was performed by ELISA. The simultaneous HIV antigen and antibody detection test was carried out. In the meantime, HIV RNA PCR and anti-HIV and anti-HIV2 western blot assays were also performed to confirm the test results in cases the test results didn't agree. The simultaneous detection kit showed 100% sensitivity and 99.6% specificity. Furthermore, the test displayed the possibility of earlier diagnosis than conventional anti-HIV1/2 ELISA with the results obtained from a group of consecutive panel sera infected with HIV. From these results, we concluded that the simultaneous HIV antigen and antibody detection test can be applied as a substitute clinical screening test in the place of conventional anti-HIV1/2 ELISA, and there is the probable benefit of early diagnosis.
Enzyme-Linked Immunosorbent Assay/standards* ; Enzyme-Linked Immunosorbent Assay/instrumentation ; HIV Antibodies/analysis* ; HIV Antigens/analysis* ; Human ; Korea ; Reagent Kits, Diagnostic/standards

AIMTo develop a rapid and inexpensive method for purification of human albumin, a method of immunomagnetic microspheres (IMMS) based on enzyme-linked immunosorbent assay (ELISA) for the purification of human albumin from human serum.

METHODSPolystyrene magnetic microspheres with carboxyl groups as carriers were prepared, and then the carboxyl groups on the surface of the microspheres were activated by ethylcarbodiimide (EDC). Finally rabbit anti-human serum albumin (HSA) antibodies were covalently bound to it and the complex can specifically capture HSA. After the procedure of capturing HSA, through taking rabbit anti-human albumin protein antibodies as a capture antibody, and goat anti-human albumin protein antibodies as a detection antibody, an ELISA on IMMS was developed, which can determine the recovery yield of HSA from the human serum.

RESULTSThe result of the experiment was that the recovery of human albumin with IMMS was (86 +/- 4)%, and IMMS were reused for two other purifying cycles, the results of which were (69.0 +/- 0.6)% and (40.8 +/- 0.8)%, and the purity of the product was about 90%.

CONCLUSIONThe results above prove that the immunomagnetic purifiying strategy was shown to be efficient and offers an new thought for a large scale production of high-purity HSA.

Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; Humans ; Immunomagnetic Separation ; methods ; Microspheres ; Polystyrenes ; chemistry ; Reproducibility of Results ; Serum Albumin ; immunology ; isolation & purification

This paper presents a vision-based method for the width of NC membrane online inspection. In the production of bio-test strip, the number of antigen or antibody which is coated on the membrane depends on the width and the uniformity of test line T and control line C. People should control the width and the uniformity strictly to ensure the accuracy of lines in order to achieve quantitative inspection with high sensitivity. And online inspection must be done, it cannot be processed when the solution has been dry up. This paper gives a design of online inspection system based on linear charge-coupled device (linear CCD), it makes such advantages in terms of speed, accuracy, and the operation to achieve real-time, online inspection.
Biosensing Techniques ; instrumentation ; Diagnostic Techniques, Ophthalmological ; Enzyme-Linked Immunosorbent Assay ; Gold Colloid ; chemistry ; Humans ; Immunosorbent Techniques ; instrumentation ; Online Systems ; Photometry ; instrumentation ; Reagent Strips ; Vision Tests ; instrumentation ; methods ; Vision, Ocular ; Visual Acuity

AIM: A quantitative ELISA kit for the detection of human secreted CD306/LAIR-2 was developed using monoclonal and polyclonal antibodies which were raised against a highly purified recombinant human secreted CD306/LAIR-2. METHODS: Anti-human secreted CD306/LAIR-2 monoclonal and polyclonal antibodies were raised by immunizing mouse or rabbit with recombinant human secreted CD306/LAIR-2. The monoclonal antibody was purified by protein G affinity, whereas the polyclonal antibody was purified by protein A affinity. The best match pair of antibodies were found and used to develop a double antibody sandwich ELISA kit for the detection of human secreted CD306/LAIR-2 in human samples. RESULTS: A human secreted CD306/LAIR-2 ELISA kit was formulated with highly purified recombinant human secreted CD306/LAIR-2, highly specific monoclonal and polyclonal antibodies. This kit realized the quantitative measurement of recombinant human CD306/LAIR-2 and natural CD306/LAIR-2 in human serum samples. CONCLUSIONS The developed human secreted CD306/LAIR-2 ELISA kit is a reliable quantitation immunoassay kit.
Animals ; Antibodies, Monoclonal ; immunology ; Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; Humans ; Mice ; Mice, Inbred BALB C ; Rabbits ; Receptors, Immunologic ; analysis ; blood ; immunology ; Recombinant Proteins

BACKGROUND: Maternal serum prenatal quadruple screening includes testing for alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), unconjugated estriol (uE3), and dimeric inhibin A (DIA). We evaluated quadruple screening using an automated platform and looked for any ethnic differences in the median values of each marker. METHODS: We measured the concentrations of each quadruple test analyte using the UniCel DxI 800 system (Beckman Coulter, USA) in 788 Korean mid-trimester maternal serum samples and calculated their median values using Benetech software (Benetech, Canada). We also compared the results with those obtained using the Immulite 2000 assay (Siemens Healthcare Diagnostics, USA) or ELISA (DSL, USA) in 442 samples. RESULTS: We obtained mid-trimester median values for each marker. The following are the comparative results for each test using the Immulite 2000 assay or ELISA (x) and the UniCel DxI 800 immunoassay (y): AFP, y=1.10x+0.01, r=0.925; uE3, y=0.28x+0.24, r=0.885; hCG, y=1.22x-3047.8, r=0.944; and DIA, y=0.86x+15.31, r=0.833. Assay results for each of the four markers showed good correlations. However, significant biases necessitated new median calculations of prenatal risk estimates in all four tests. CONCLUSIONS: We established gestational age-specific second-trimester median values for four markers in Korean samples using the UniCel DxI 800 immunoassay system. Despite significant bias, there were good correlations between the results obtained using the UniCel DxI 800 immunoassay and those obtained using the Immulite 2000 assay.
Biological Markers/blood ; Chorionic Gonadotropin/blood ; Enzyme-Linked Immunosorbent Assay ; Estriol/blood ; Female ; Gestational Age ; Humans ; Immunoassay/instrumentation/*methods ; Inhibins/blood ; Pregnancy ; Pregnancy Trimester, Second ; *Prenatal Diagnosis ; Reference Values ; Republic of Korea ; alpha-Fetoproteins/analysis

OBJECTIVETo evaluate the quality of the ELISA diagnostic kits for detecting hepatitis E virus (HEV) specific IgG antibody.

METHODSFive diagnostic kits (WT, GD, HM, GeneLabs and KH) for anti-HEV IgG were assayed by detecting HEV IgG in the HEV diagnostic reference sera from 24 positive cases and 30 negative cases. 42 cases clinical suspect patients with hepatitis E from Ditan hospital in Beijing in 1994 to 1995 and 230 normal persons' sera from Chengdu city, Sichuan province in September in 2005.

RESULTSThe conformity rates of positive and negative sera was 95.83% (23) and 96.67% (29) for WT kit, 87.50% (21) and 100% (30) for GD kit, 87.50% (21) and 96.67% (29) for HM kit, 66.67% (16) and 100% (30) for GeneLabs kit, 45.83% (11) and 100% (30) for KH kit for detecting anti-HEV positive and negative reference sera, respectively. The five kits were used to detect anti-HEV IgG among 42 clinical suspect patients with hepatitis E and 230 normal persons' sera, The positive rate was 97.62% (41) and 31.74% (73) by WT, 100% (42) and 17.39% (40) by GD kit, 97.62% (41) and 23.91% (55) by HM kit, 90.48% (38) and 7.83% (18) by GeneLabs kit, 90.48% (38) and 3.48% (8) by KH, respectively.

CONCLUSIONThe positive rates of all the 5 kits were over 90% and had a very high conformity in detecting anti-HEV IgG in clinical patient with hepatitis E, positive rates of 3.48% to 31.74% were found in detecting the normal persons' sera. The research showed insufficiency of the ELISA kits for epidemiological survey of HEV infection in population.

Adolescent ; Adult ; China ; Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; Hepatitis Antibodies ; blood ; Hepatitis E ; blood ; diagnosis ; virology ; Humans ; Immunoglobulin G ; blood ; Reagent Kits, Diagnostic ; standards ; Reproducibility of Results ; Sensitivity and Specificity ; Young Adult

BACKGROUNDTo evaluate homemade and imported HbsAg ELISA kits on screening blood donors.

METHODSSamples for evaluation included 120 HbsAg serum plates for the golden criteria and 400 sets of serum from blood donors in Dongguan. The samples underwent blind screening with homemade and imported ELISA kits respectively.

RESULTSThe sensitivity of homemade (Xinchuang) and imported (Diasorin) HbsAg ELISA kit were 85.71% (72/84) and 100% (84/84), respectively. Their specificity was 100% (436/436) and 96.55% (421/436) respectively. The consistency of two ELISA kits was 100%.

CONCLUSIONThe imported ELISA kit had the highest sensitivity, but its specificity was not as good as that of homemade ELISA kit. The two kinds of ELISA kits had good repetition. The combination of the two reagents may ensure the safety of blood transfusion.

Blood Donors ; China ; Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; standards ; Hepatitis B ; blood ; diagnosis ; prevention & control ; Hepatitis B Surface Antigens ; blood ; Humans ; Mass Screening ; methods ; standards ; Reagent Kits, Diagnostic ; standards ; Reference Standards ; Reproducibility of Results ; Sensitivity and Specificity

OBJECTIVETo establish a specific and sensitive serological ELISA, diagnostic method, for herpes simplex virus-1 (HSV-1) infection using yeast expressed glycoprotein D (gD) of HSV-1 as coating antigen.

METHODSThe yeast expressed products were collected at the most appropriate time and sonicated. After the optimum dilution titers of the coating antigens and sera were determined, 57 clinical sera were assayed using the recombinant gD and HSV-1-infected culture media as coating antigens respectively. The same sera were also assayed by homemade and Euroimmun ELISA kit, Germany. The results of German kit as a golden standard were compared with those of the other three methods in specificity, sensitivity and accordance rate.

RESULTSCompared to the imported kit, the specificities of recombinant protein, HSV-I culture media and homemade kit were 57.1%, 57.1% and 100.0%, respectively, the sensitivities were 82.0%, 78.0%, 48.0% and the accordance rates were 78.9%, 75.4%, 54.4%, respectively. The results of repeated experiments of recombinant protein showed that there was no statistically significant difference between the two experiments (P > 0.05).

CONCLUSIONThe ELISA with recombinant gD protein of HSV-1 as coating antigen is a specific, sensitive, quick and convenient method for diagnosis of HSV-1 infection.

Animals ; Antibodies, Viral ; blood ; immunology ; Antigens, Viral ; immunology ; Cell Line ; Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; Herpes Simplex ; blood ; diagnosis ; virology ; Herpesvirus 1, Human ; genetics ; immunology ; Humans ; Recombinant Proteins ; immunology ; Reproducibility of Results ; Sensitivity and Specificity ; Viral Envelope Proteins ; genetics ; immunology

The Rhei Radix et Rhizoma was one of the most widely used traditional Chinese medicine for its special biological activities. The content of rhein, one of its major compounds, was an important standard for the quantity control of Rhei Radix et Rhizoma. The major method used for the detection of rhein was instrumental analysis like HPLC, but it was complex, time-consuming and cannot detect large samples at the same time. The enzyme-linked imunmosorbent assay (ELISA) was accurate, reliable, simple, low costs, and of a high-throughout. Recently, it was widely used for the determination of those small molecule compounds in some traditional Chinese medicinal plants. In this study, an artificial antigen were synthesized by the carbodiimide (CDI) method. Rhein-bovine (rhein-BSA) conju gate and rhein-ovalbumin (rhein-OVA) conjugate, were produced as the immunogen and coating antigen, respectively. The conjugate and the hapten number in the conjugate were determined by UV-Vis spectrophotometry (UV). The conjugation ratio of Rhein and BSA was about 4.0:1, rhein acid and OVA was 2.6 : 1, respectively. Rhein-BSA conjugate was used to immunize Bal b/c mice to produce antiserum. The antiserum titer of the Rhein were higher than 8000 detected by ELISA. The successfully synthesized conjugate antigen rhein-BSA implies its feasibility in the establishment of fast immunoassay for the rhein content determination.
Animals ; Anthraquinones ; analysis ; immunology ; Antibodies ; analysis ; immunology ; Antigens, Plant ; analysis ; immunology ; Drugs, Chinese Herbal ; analysis ; Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; Mice ; Mice, Inbred BALB C ; Rheum ; chemistry ; immunology ; Rhizome ; chemistry ; immunology

BACKGROUND/AIMS: M2 pyruvate kinase (M2-PK) is an enzyme that is produced in undifferentiated and proliferating tissues. This study aims to evaluate the usefulness of the immunochromatographic M2 pyruvate kinase (iM2-PK) for the screening of colorectal cancer (CRC) and premalignant lesions. METHODS: Healthy volunteers and patients with colorectal neoplasia were enrolled in six academic hospitals in the capital province of Korea. The iM2-PK value was compared with the immunochromatographic fecal occult blood test (iFOBT) and fecal tumor M2-PK enzyme-linked immunosorbent assay (ELISA). RESULTS: A total of 323 subjects were enrolled. The sensitivity of iM2-PK for CRC was 92.8%, which was superior to iFOBT (47.5%, p<0.0001). For adenomatous lesions, the sensitivity of iM2-PK was 69.4%, which was also superior to iFOBT (12.1%, p<0.001). Compared with M2-PK ELISA, iM2-PK exhibited significantly enhanced sensitivity for CRC (97.5% vs 80.0%, p=0.0289). The sensitivity of iM2-PK was higher in advanced stages of CRC compared with cancers confined to the mucosa and submucosa (p<0.05). However, lymph node metastasis had no influence on the sensitivity of iM2-PK. CONCLUSIONS: The iM2-PK exhibited increased sensitivity for identifying CRC and adenomatous lesions compared with iFOBT. Given its rapid results and convenience, CRC screening using iM2-PK is promising.
Adenoma/*diagnosis ; Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor/*analysis ; Clinical Enzyme Tests/*instrumentation ; Colorectal Neoplasms/*diagnosis ; Enzyme-Linked Immunosorbent Assay ; Feces/*enzymology ; Female ; Healthy Volunteers ; Humans ; Immunochromatography/methods ; Male ; Middle Aged ; Occult Blood ; Precancerous Conditions/diagnosis/enzymology ; Predictive Value of Tests ; Pyruvate Kinase/*analysis ; Reagent Kits, Diagnostic ; Republic of Korea ; Sensitivity and Specificity