UBI® HCV EIA

DIRECTION INSERT
PERFORMANCE CHARACTERISTICS

Product Description
The UBI® HCV EIA test is an enzyme-linked immunosorbent assay for the qualitative detection of circulating antibodies to the Hepatitis C Virus in human serum or plasma. The in vitro diagnostic test is based on immunosorped synthetic peptides to the NS-3 and the NS-4 proteins of the Hepatitis C virus on a 96-well microtiter plate.

UBI has been marketing immunodiagnostic tests for Hepatitis C virus (HCV) since 1991 through a marketing partner, BioMerieux. The UBI® SYN PEP II HCV EIA was approved for sale within Japan by Koseisho Hal (the Japanese Ministry of Health and Welfare) in 1996. The UBI® HCV EIA was approved for sale within China in 1996, and the kit is also licensed for sale in Taiwan in 2002.

The screening of donated blood for Hepatitis C is mandatory in virtually all countries of the world, because Hepatitis C is considered to be the viral hepatitis with the most severe long-term consequences to chronic carriers, and is readily transmissible through blood transfusions and other situations that involve exposure to blood or blood products.

This screening test, with a total incubation time of 2 hours, is a fast, easy to use TMB substrate based EIA. Total run time is generally less than 2.5 hours and allows rapid daily sample throughput. UBI® HCV EIA was designed for the direct inoculation of sample and controls to the reaction plate and thus the test is compatible with many automated sample handling systems such as the Hamilton AT series and other open systems.

The UBI® HCV EIA test is licensed for use with fresh or frozen sera and plasma. The sample is diluted 1:11 in a sample diluent on the antigen-coated microplate wells, incubated for 60 minutes at 37°C, and washed with a saline-based buffer. A dilute solution of HRP-conjugated anti-Human IgG is added to the microplate wells, incubated for 30 minutes at 37°C, and is washed again. The TMB substrate solution is easy to prepare by pouring the substrate solution to the TMB solution and maintaining the solution in the amber bottle until ready to use. After TMB substrate solution is added to the microplate wells, the plate has a final 30 minute incubation at 23°C or ambient room temperature. A dilute solution of 1 molar sulfuric acid is added to the microplate wells to halt the TMB-HRP reaction. The microplate may be read at 450 nm to obtain absorbance values to calculate a relative signal-to-cutoff ratio based on the absorbance of the positive control sera provided in the kit. Those wells which are yellow reflect the colorimetric reaction of the antigen-antibody-HRP-TMB complex that indicates the presence of antibodies to the Hepatitis C virus in the test sample.

Product Specifications
Catalog # 600061, UBI® HCV EIA kit, 192 tests
Catalog # 600318, UBI® HCV EIA kit, 576 tests
The shelf life of the UBI® HCV EIA kit is 24 months when stored at at 2-8°C

The UBI® HCV EIA kit is provided in convenient modular microplate strip plates to accommodate small volume users such as hospitals and clinics as well as higher throughput blood banks or reference laboratories.

Primary packaging emphasizes safety to the end-user while meeting all shipping safety requirements. Secondary packaging is completely recyclable and bio-degradable.

The UBI® HCV EIA may be used on any open sample handling system and with any incubation system – convection air, static air or water bath. The test may be easily performed for as few as two test samples and as many as 92 test samples per microplate.

Sensitivity Results from Mixed and Low Titer Performance Panels
The evaluations were carried out using six panels totaling to 74 serum specimens (as shown in Table 1). The six Boston Biomedica Inc. (BBI) mixed and low titer performance panels contain clinically diagnosed positive samples. All specimens were stored in aliquots at -30°C and were thawed at least once and not more than twice.

In this model of HCV infection, the sensitivity of the UBI HCV EIA was determined to be 98.65% for positive samples.

Table 1.Summary of UBI HCV EIA Sensitivity Results from Mixed and Low Titer Performance Panels

BBI HCV Panel CodeNumber of Samples**Number
reactive by test
PHV1031111
PHV1041414
PHV1051313
PHV2021918
PHV2031616
PHV20411
Total7473
Sensitivity98.65%

* Only one member from PHV204, PHV204-15, of anti-NS3 antibody predominance, was assayed.** After culling panel members that test Ortho 3.0 EIA negative.BBI, Boston Biomedica Inc., West Bridgewater, MA, USA

Relative Sensitivity Performance on Seroconversion Panels
For evaluation, specimens in nine seroconversion panels (BBI), were screened by two reference ELISAs, the Ortho HCV 3.0 (Ortho Clinical Diagnostics) and the Abbott anti-HCV 3.0 (Abbott. Diagnostics) and the results compared to the UBI HCV EIA to determine relative performance on these seroconversion panels.

Each of the nine seroconversion panels consists of a series of sera collected from time sequential bleeds from a single HCV infected patient. Each of the bleeds were taken at different time intervals early in the infection (window) period.

The HCV antibodies of the infected patients, tested by the UBI HCV EIA, the Ortho HCV 3.0 and the Abbott anti-HCV 3.0, were detected by 0-28, 7-32, 8-28 day post-HCV infection, (mean were 14, 29 and 17 days) respectively.

The results (Table 2) are shown for the interpretation of each serum based on the criteria of the UBI HCV EIA, Ortho HCV 3.0, and Abbott anti-HCV 3.0 kits. “Detected Day Since First Bleed” indicates the average minimum day by which each kit detected infection in each of the seroconversion panels. The result shows that the average of minimum day of detection by the UBI HCV EIA was 14 days and it is the earliest relative performance among these HCV kits.

Table 2. UBI HCV EIA Sensitivity

BBI Anti-HCV Seroconversion series Code Detection Day Since First Bleed
UBI HCV BBI report Abbott 3.0 EIA BBI report Ortho 3.0 EIA
PHV904 14 14 14
PHV904 18 25 21
PHV904 0 7 0
PHV904 13 21 21
PHV904 19 32 19
PHV904 28 28 28
PHV904 8 8 8
PHV904 14 14 14
PHV904 16 19 24
Average detected days since 1st bleed 14 19 17



Summary of EIA Specificity
An independent measurement of assay specificity considers the repeatability of the sample’s reactivities (as the S/C ratio) of UBI HCV EIA.

A naïve panel of 1997 normal blood donor sera, were tested on UBI HCV EIA kits. Specimens with absorbance values less than the Cut-off VALUE were considered non-reactive by the criteria of the UBI HCV EIA and were considered negative for antibodies to infectious HCV.

A total of 1994 samples were found negative in the EIA. Three samples were repeatably reactive, giving rise to a 0.15% repeatably reactive rate for the UBI HCV EIA kit. UBI HCV EIA, as shown, demonstrated excellent specificity at a rate greater than 99.8% in the screening of naive human sera from normal blood donors.

Table 3. Summary of EIA Specificity Test for UBI HCV

HCV

Number of Test Samples 1997
Number of Repeatably Reactive 3
Repeatably Reactive Rate 0.15%

Florida Blood Services, St. Petersburg, FL, USA