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

OBJECTIVETo develop a double antibody sandwich ELISA assay for quantitative determination of recombinant human interferon alpha1b.

METHODSMouse monoclonal antibodies with different binding site on rIFN-alpha1b were screened to select optimized candidates as coating and HRP-labeled index antibodies respectively. And a double antibodies sandwich ELISA was assembled; the reliable lower detection limit, specificity, accuracy and reproducibility were evaluated and validated.

RESULTSThe quantitative sandwich ELISA had a reliable lower detection limit of 10 ng/ml, with a liner detection range 10-100 ng/ml (R2 = 0.992), variation coefficient inter-plates is less than 10%.

CONCLUSIONThe developed sandwich ELISA was a sensitive and specific, accuracy and reproducibility method for quantitative determination of recombinant human interferon alpha1b in final product.

Animals ; Antibodies, Monoclonal ; analysis ; Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; Humans ; Interferon-alpha ; blood ; Mice ; Mice, Inbred BALB C

OBJECTIVETo analyze the clinical performance of TP antibody detection by CLIA kits and evaluate whether the CLIA kits made in China is suitable for clinical use.

METHODS1200 samples were collected from Beijing Hospital including 300 samples with confirmed TP infection and 900 healthy control samples. To detect the TP antibody of the 1200 sanples separately by the CLIA kits and the ELISA kits at the same time. The test results were analyzed with statistical methods.

RESULTSThe sensitivity and specificity of the CLIA kits were 99.3% and 99.9% respectively, and positive predictive value of 99.7%, negative predictive value of 100%. With the ELISA method, the positive coincidence rate was 98.7%, the negative coincidence rate was 99.8%, and the total coincidence rate was 99.5%.

CONCLUSIONThe CLIA kits showed good clinical performance and the agreement rate with the ELISA kits was. The CLIA kits are suitable for clinical use.

Antibodies, Bacterial ; blood ; China ; Enzyme-Linked Immunosorbent Assay ; economics ; instrumentation ; methods ; Humans ; Luminescent Measurements ; economics ; instrumentation ; methods ; Reagent Kits, Diagnostic ; economics ; Sensitivity and Specificity ; Syphilis ; blood ; diagnosis ; Syphilis Serodiagnosis

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

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

OBJECTIVEThis study compared two newborn Cytomegalovirus (CMV) IgG antibody screening ELISA kits and evaluated the detection effectiveness of Abnova kit.

METHODSCMV IgG antibodies were detected by both SeraQuest and Abnova kits from dried blood spot (DBS) samples of 488 newborn heel sticks. The detection abilities of these two kits were compared in different sample dilution concentrations. Relative detection effectiveness of the Abnova kit was defined by statistical method using the SeraQuest kit as a point of comparison.

RESULTCompared to the SeraQuest screening test kit, the Abnova kit revealed a sensitivity of 98.9%, specificity of 78.6%, positive predictive value of 99.3%, negative predictive value of 68.8%, and the coincidence rate for these two screening test kits at 98.3%. The consistency check of both kits based on interpretation of the kappa statistic was relatively good. For the Abnova kit, the "area under the ROC curve" was 0.887, which indicates moderate accuracy.

CONCLUSIONAbnova kit can be applied to newborn screening for congenital CMV infections. However, repeating the test for ambiguous results is suggested to increase the specificity and negative predictive value.

Antibodies, Viral ; blood ; Cytomegalovirus ; immunology ; isolation & purification ; Cytomegalovirus Infections ; blood ; diagnosis ; virology ; Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; Female ; Humans ; Immunoglobulin G ; blood ; Infant ; Infant, Newborn ; Male ; Neonatal Screening ; methods ; Reagent Kits, Diagnostic

OBJECTIVETo establish chemiluminescence enzyme immunoassay (CLEIA) for quantitative detection of procollagen III N-terminal peptide (P III NP) in serum.

METHODSA sandwich reaction was preformed with horseradish peroxidase labeled monoclonal antibody of P III NP as the catalytic enzyme and the luminol as the luminescence reagent. Several reactions liquid's concentration and reaction conditions were optimized. The method was evaluated in all aspects such as linear range, sensitivity, specificity, stability and so on. The CLEIA was compared with imported ELISA kits, by detecting clinical serum.

RESULTSThe linear range was 0.8-85 ng/ml. The detection limit was 0.5 ng/ml. Inter-assay and intra-assay RSD were both less than 10%. The recoveries of three different spiked concentration samples were 96.2%, 91.2% and 101.1%. After stored at 4 degrees C and 37 degrees C for 3, 5, 7 days, the analysis showed correlation coefficient higher than 0.99 and RSD lower than 6%. The detected results of clinical sera with CLEIA closely corresponded to those with imported ELISA.

CONCLUSIONEstablished CLEIA for quantity determination of serum P III NP has high accuracy, sensitivity and repeatability.

Adult ; Aged ; Antibodies, Monoclonal ; analysis ; Enzyme-Linked Immunosorbent Assay ; instrumentation ; methods ; Female ; Humans ; Liver Cirrhosis ; blood ; diagnosis ; Luminescence ; Luminescent Measurements ; methods ; Male ; Middle Aged ; Peptide Fragments ; blood ; chemistry ; Procollagen ; blood ; chemistry ; Sensitivity and Specificity