HIV Detection: Be A Part of the Solution
As the Human Immunodeficiency Virus (HIV) reaches epidemic numbers, health officials are recognizing the disease as a major heath concern throughout the world. Although this disease has no current cure, it is obvious that detection is one key for prevention. At BioLink International we are working to provide the materials necessary for creating cost-effective detection of this deadly disease.
Various HIV gene fragments have been cloned in our Laboratory of Molecular Virology in Beijing, China. These fragments include gag, pol, env genes of HIV. Many epitopes have been synthesized including the main epitope gene of the putative HIV-1 O group. This newly discovered O subgroup of HIV-1 cannot be detected by some commercial HIV ELISA kits because of its distinction from the major O group in sequence. A Multi-epitope Chimeric HIV Antigen, which contains a lengthened HIV-1 gp41, O IDR(immune-domain region), has been developed and only one of such a chimera antigen can be used in EIA kit to gain satisfactory sensitivity and specificity. BioLink has the O subgroup antigen available in its pure form or in combination with gp 41 and gp 36. We have also constructed many expression plasmids of chimera genes that contain different HIV subtype epitopes expressed in a fusion manner.
Each of the recombinant antigens listed has been cloned, expressed (in E. Coli) and purified (> 95%). They can be purchased in a LIA kit format or as multi-epitope Chimeric antigens. We currently provide raw materials for purpose of research and manufacturing. We specialize in Recombinant Antigen for HIV, HCV, and Syphilis. These products are suitable for RIBA (LIA) kits.
HCV Antigens to Help with Disease Diagnosis and Diagnosis
Hepatitis C Virus is a growing disease in western society. As our medical management options increase so does the need for efficient screening for the disease and evaluation of treatment.
A study was recently performed to to evaluate the correlation between total Hepatitis C virus (HCV) Core antigen (Ag) and HCV-RNA, and to assess the proficiency of HCV Core Ag testing in monitoring and predicting virologic response during and after pegylated interferon (PEG-IFN) and ribavirin combination therapy. For HCV Core Ag the negative predictive value (NPV) was 100% whereas for HCV-RNA the NPV was 80% (P > 0.05). At month 1, the PPV was 95% and 100% when determined by HCV Core Ag and HCV-RNA, respectively. The NPV value was 100% for HCV Core Ag and 33% for HCV-RNA (P = 0.005).
The study conclude that HCV Core Ag quantification could be useful in clinical practice to predict a sustained virological response early during therapy (4 weeks), reaching an optimal performance at month 3. The determination of total HCV Core Ag levels in serum, constitutes an accurate and reliable alternative to HCV-RNA for monitoring and predicting treatment outcome in patients receiving PEG-IFN/Ribavirin combination therapy. The recent increase in HCV treatment success observed with pegylated interferon (PEG-IFN) plus ribavirin, will lead to a significant increase in the number of patients gaining access to treatment. This has created a demand for fast, easy to perform, reproducible, alternative viral load tests.
The core antigen (Ag) of HCV constitutes an alternative direct marker to RNA for assessing the levels of viremia in HCV-seropositive patients. The determination of total HCV core Ag levels in serum constitutes an accurate and reliable alternative to HCV RNA for monitoring and predicting treatment outcome in patients receiving PEG-IFN/Rib combination therapy.
BioLink Inc. has the HCV core antigen as well as many others to provide researchers and development companies the opportunity to gain an edge on this potential market.
Antigens For Diagnosis of Treponema Pallidum
Syphilis is one of the most prevalent sexually transmitted infections worldwide. Its control and surveillance require careful screening tests by reliable methods.
Syphilis is one of the most prevalent sexually transmitted infections worldwide. Its control and surveillance require careful screening tests by reliable methods. There is a need for a reliable, specific, rapid and automated test for the screening and confirmation of syphilis. EIAs for this purpose have shown sensitivity and specificity in one study to be (96.1% and 100% respectively).
Another study did a comparison of an enzyme immunoassay (EIA) using two major Treponema pallidum recombinant antigens with a T. pallidum hemagglutination (TPHA) assay and a nontreponemal Venereal Disease Reference Laboratory (VDRL) test. A total of 1,822 normal donor serum samples was tested for cardiolipin and T. pallidum antibodies, respectively, by the VDRL assay and EIA. Among these samples, 440 were further tested by TPHA technology. Four samples were found positive by EIA, while all were reported to be negative by both TPHA and VDRL routine assays. Subsequent testing of EIA-positive samples confirmed 100% (four of four samples) and 25% (one of four samples) positive results, respectively, by immunofluorescence assay and a Western blot (immunoblot) syphilis kit. The sensitivity of the recombinant EIA was estimated at virtually 100% with a reference panel of 50 syphilitic samples. According to this study, the newly developed EIA kit shows 100% sensitivity combined to a specificity greater than 99.8% for detecting treponemal immunoglobulin G antibodies in blood bank syphilis screening.
Our Recombinant Tp-chimeric protein contains TpN 15, TpN17, TpN44.5 & TpN47 fragment. Only one such chimera antigen will achieve a satisfactory level of sensitivity and specificity in Syphilis EIA kit testing. We also provide single antigens including TpN 15 protein, TpN 17 protein, TpN 44.5 protein, TpN 47 protein. It it our pleasure that our products can help to diagnosis and prevent those devastating diseases.