Hepatitis C virus Ab ELISA Kit

Transcription

1 Hepatitis C virus Ab ELISA Kit Catalog Number KA assays Version: 16 Intended for research use only

2 Table of Contents Introduction... 3 Intended Use... 3 Principle of the Assay... 3 General Information... 4 Materials Supplied... 4 Storage Instruction... 4 Materials Required but Not Supplied... 5 Precautions for Use... 5 Assay Protocol... 7 Reagent Preparation... 7 Sample Preparation... 8 Assay Procedure... 8 Data Analysis Calculation of Results Performance Characteristics Resources References Plate Layout KA / 16

3 Introduction Intended Use Hepatitis C virus Ab ELISA Kit is an enzyme immunoassay kit for qualitative detection of Antibody to Hepatitis C virus (anti-hcv) in human serum or plasma. Principle of the Assay This kit adopts the "direct sandwich principle" as the basis for the assay to detect antibodies to Hepatitis C virus (anti-hcv) in human serum or plasma. It is a fourth generation enzyme immunoassay kit, which uses recombinant HCV antigens (Core, NS3 and NS5 antigens) for the detection of Antibody to Hepatitis C virus (anti-hcv) in human serum or plasma. 1-3 These antigens, which are reactive with the predominant antibodies of HCV, constitute the solid phase antigenic absorbent. When human serum or plasma is added to the well, the HCV antigens and Anti-HCV will form complexes on the wells if Anti-HCV is present in the specimen. The wells are washed to remove the unbound materials. The diluted HCV Ag HRPO Conjugate is added to the well and results in the formation of (HCV Ag) (Anti-HCV) (HCV Ag HRPO) complex. After washing out the unbound conjugate, TMB substrate solution is added for color development. The intensity of color development is proportional to the amount of antibodies present in the specimen. KA / 16

4 General Information Materials Supplied List of component Component Description Amount HCV Antigens Plate Conc. HCV Ag HRPO Conjugate Anti-HCV Positive Control HCV Negative Control Conjugate Diluent 96-well microtiter plate coated with HCV Core antigens, 1 plate NS3 and NS5 antigens. Contained HCV Ag Peroxidase (Horseradish) in buffer with Bovine serum. 1.8 ml Preservatives: 0.05 % Sodium azide and 0.1% Amaranth. Inactivated human plasma positive for Anti-HCV. 2 ml Preservative: 0.099% Sodium azide. Normal human plasma non-reactive for Anti-HCV. 3 ml Preservative: 0.099% Sodium azide. PB-buffer with Bovine serum and Tween ml Preservatives: 0.05 % Sodium azide. TMB Substrate Solution A 3, 3, 5, 5 -tetramethylbenzidine (TMB) 12 ml TMB Substrate Solution B Acetate Buffer with Urea Hydrogen Peroxidase. 12 ml Conc. Washing Solution D (20X) Phosphate buffer with Tween ml 1 N H 2 SO 4 1 N Sulfuric Acid 12 ml Accessories: (provided as needed) Component Adhesive slips Black cover Amount X1 X1 Storage Instruction 1. The kit must be stored at 2 to 8 C. Do not freeze. 2. Strips of the plate should be used within one month once the original aluminum foil bag is opened. The unused strips should be kept in the aluminum foil bag and taped the opening tightly. 3. Return reagents to 2 to 8 C immediately after use. 4. Washing Solution D (20X) Concentrate can be stored at room temperature to avoid crystallization. If the crystal has been precipitated before use, warm up the solution in 37 C water bath till crystal dissolved. KA / 16

5 Materials Required but Not Supplied 96-well plate for specimen dilution. 10 µl, 100 µl, 200 µl and 1 ml micropipettes and tips are needed. Plate washing equipment. Water-bath or incubator. ELISA microwell reader: Dual wavelength 450 nm with 620 to 650 nm as reference wavelength, bandwidth 10 nm. Purified water: distilled or deionized water. Fully automatic EIA micro-plate analyzer is optional. User should validate the automatic EIA micro-plate analyzer in combination with the kit. Precautions for Use For professional use only. Bring all kit reagents and samples to room temperature (20 to 30 C) and mix gently before use. Do not use reagent beyond its expiration date. Do not interchange reagents between different lots. Reagents must be protected from microbial contamination. Although all human sourced material are tested free from HBsAg and Anti-HIV and inactivated at 56 C for one hour, the reagent should still be handled as potential infectious material. Do not smoke or eat in areas where specimens or reagents are handled. Do not pipette in the mouth. All kit components and specimens should be regarded as potential hazards to health. It should be used and discarded according to your own laboratory s safety procedures. Such safety procedures probably will include the wearing of protective gloves and avoiding the generation of aerosols. Potential infectious specimens and nonacid containing spills or leakages should be wiped up thoroughly with 5% sodium hypochlorite or treated in accordance with the laboratory s practice for potential bio-hazard control. Prior to dispose the waste of used specimens and kit reagents as general waste, it should be treated in accordance with the local procedures for potential bio-hazardous waste or treated as follows: Both liquid and solid waste should be autoclaved maintaining 121 C for at least 1 hour. Solid waste can also be incinerated. Non-acidic liquid waste can be treated with sodium hypochlorite diluted to a final concentration of 1%. Acidic liquid wastes must be neutralized before treatment with sodium hypochlorite as mentioned above and should stand for 30 minutes to obtain effective disinfection. 1 N Sulfuric Acid is an irritant to skin, eyes, respiratory tract and mucous membranes. Avoid contact of the 1 N sulfuric acid with skin and mucous membranes. In case of contact, flush immediately with KA / 16

6 abundant amounts of water. In case of inhalation, find fresh air immediately and seek medical advice in case of pain. TMB substrate solution A contains organic solvent, which is flammable. TMB substrate solution A contains dimethyl sulfoxide, an irritant to skin and mucous membranes. KA / 16

7 Assay Protocol Reagent Preparation Plate Washing Procedure Preparation of washing solution: Dilute Conc. Washing Solution D (20X) with distilled or de-ionized water to 1:20 dilution. Do not use tap water. Automatic or Semi-automatic Plate Washer Any commercial automatic microplate washer or other liquid aspirating/dispensing devices can be used for washing purpose. The user should test the devices to determine the proper volume of water and wash cycles to insure proper washing. We suggested 6 wash cycles with at least 0.4 ml per well per wash and soaking for 10 seconds is necessary. Blot dry by inverting the plate and tapping firmly onto absorbent paper. Too much residual wash buffer will cause false results. WARNING: Improper washing will cause false results. Preparation of HCV Ag HRPO conjugate a. Conc. HCV Ag HRPO Conjugate and Conjugate Diluent need to return to room temperature before mixing. b. Use only clean container to avoid contamination. c. Prepare diluted conjugate by making 1:20 dilution of Conc. HCV Ag HRPO conjugate with conjugate diluent, or following Conjugate Preparation Chart below. Swirl gently to mix thoroughly and avoid foaming. d. The diluted HCV Ag HRPO conjugate is best used within 6 hours at room temperature or within 2 days at 2-8 C. Conjugate Preparation Chart: Number of wells Volume of Conjugate Diluent (ml) Volume of Conc. HCV Ag HRPO conjugate (µl) KA / 16

8 Sample Preparation Specimen Collection and Storage Either serum or plasma can be used with this kit. Whole blood specimens should be separated as soon as possible in order to avoid hemolysis. Any particulates (e.g. fibrin clots, erythrocytes) contained in the specimen should be removed prior to use. Specimens must be stored at 2 to 8 C and avoided heat-inactivation to minimize deterioration. For long-term storage, samples should be frozen below -20 C. Storage in self-defrosting freezer is not recommended. Frozen specimens must be thoroughly thawed and mixed homogenously before test. Avoid multiple freeze-thaw procedures. Incompletely coagulated sera and microbial-contaminated specimens should not be used. Assay Procedure 1. Bring all reagents and specimens to room temperature (20 to 30 C) before assay. Adjust water bath or incubator to 37±1 C. NOTE: Use a new pipette tip after each sampling to avoid cross-contamination. 2. Reserve 1 well for blank. Do not add any specimen or diluted conjugate into the well for blank. 3. Prepare the needed number of wells, including 1 well for Blank, 3 wells for Negative Control, 2 wells for Positive Control, and 1 well for each Specimen. 4. Add 100 µl of Positive Control, Negative Control and specimen to each appropriate well of HCV Antigens Plate. Mix well by tapping the plate gently. 5. Seal the Plate with an Adhesive Slip. Incubate the plate in a 37 C water bath or circuited incubator for 60 minutes. NOTE: Do not stack plates. 6. At the end of the incubation period, remove carefully the adhesive slip and discard. Wash the plate according to Plate Washing Procedure. 7. Add 100 µl of the Diluted Conjugate in each well, except the blank. Seal the plate with an Adhesive Slip. Incubate the Plate in a 37 C water bath or circulated incubator for 30 minutes. 8. Repeat step Select one of the following methods for color development: NOTE: TMB Substrate Solution A should be colorless to light blue; otherwise, it should be discarded. The mixture of TMB Substrate Solution A and B should be used within 6 hours after mix. The mixture should be avoided from intense light. Mix equal volumes of TMB Substrate Solution A and B in a clean container immediately prior to use. Add 100 µl of the mixture solution to each well including the blank. KA / 16

9 Add 50 µl of TMB Substrate Solution A first, and then add 50 µl of TMB Substrate Solution B into each well including the blank. Carefully mix well. 10. Seal the plate with a black cover and incubate in a 37 C incubator for 15 minutes. 11. Stop the reaction by adding 100 µl of 1 N H 2 SO 4 to each well including the blank. 12. Determine the absorbance of Controls and test specimens within 30 minutes, measured at 450 nm with a selected reference wavelength within 620 to 650 nm. Use the blank well to blank the spectrophotomer. NOTE: 1. The color of the blank should be colorless to light yellowish; otherwise, the test results are invalid. 2. Substrate blank: absorbance value must be less than KA / 16

10 Data Analysis Calculation of Results 1. Calculation of the NCx (Mean Absorbance of Negative Control). Example: Sample No. Absorbance NCx = ( ) / 3 = NCx must 0.2, otherwise the test is invalid. 2. Calculation of PCx (Mean Absorbance of Positive Control) Example: Sample No. Absorbance PCx = ( ) / 2 = PCx must 0.6, otherwise the test is invalid. 3. Calculation of P-N Value P-N = PCx - NCx Example: P - N = = P-N value must 0.40, otherwise the test is invalid. 4. Calculation of the Cutoff Value Cutoff Value = NCx Example: Cutoff Value = = Calculate the cut-off index of the specimens Cutoff Index = Sample OD Value / Cutoff Value Example: Sample Value is Cutoff Index = / = 4 KA / 16

11 Result Interpretation 1. Specimens with O.D. values LOWER than the Cutoff Value are considered NON-REACTIVE 2. Specimens with O.D. values GREATER than or EQUAL to the Cutoff Value are considered as initially REACTIVE and should be re-tested duplicate. If the result of specimens with CUTOFF INDEX 1.0 are considered REACTIVE. 3. Initially reactive specimens, of which both CUTOFF INDEXES of the duplicate retest are LESS than 1.0, will be considered NON-REACTIVE for Anti-HCV. 4. If one of the two CUTOFF INDEXES of the duplicate is GREATER than 1.0 but LESS than 1.5, the specimen may be interpreted as QUESTIONABLE. 5. If one of the CUTOFF INDEX of the duplicate is GREATER than 1.5 and the other one is LESS than 1.0, this indicates unusual experimental error. The test should be repeated again. Performance Characteristics Specimen Specificity The specificity was validated by 3 different facilities with more than 200 samples each. The specificity of this kit is 99%. (Data presented below) Facility A Result \ Method Other commercial product This Kit Reactive Non-reactive Sample (Total) Specificity=191/191=100% Facility B Result \ Method Other commercial product This Kit Reactive Non-reactive Sample (Total) Specificity=189/190=99.47% Facility C Result \ Method Other commercial product This Kit Reactive Non-reactive Sample (Total) Specificity=206/208=99% KA / 16

12 Specimen Sensitivity Test 1 Validation Result \ Method Other commercial product This Kit Reactive Non-reactive IND 6 6 Sample (Total) Test 2 Validation of sensitivity with 60 samples was found all reactive. Sensitivity For the 2 tests above, it is concluded that the sensitivity of this kit is 100%. Analytical Specificity The analytical specificity was validated by 3 kits with 200 HCV negative specimens. All results were negative. The specificity of this kit is 100%. Analytical Precision The precision of this kit was validated by using 3 kits to detect 4 Anti-HCV positive specimens under different concentrations. Intra-run (Average CV%) Inter-run (Average CV%) Positive control Specimen Specimen Specimen CV% Average CV% Positive control 6.08 Specimen Specimen Specimen CV% 20 KA / 16

13 Genotype of Anti-HCV The precision of HCV genotype 1-6 was validated by this kit to detect 83 specimens. All results are REACTIVE. HCV genotype specimen HCV genotype specimen a/1b 1 4a 7 1b 15 4 non a 3 2a 15 4c/4d 3 2a/2c 2 5a a 1 3a Interference of other disease or physiological condition Disease Other products KA2534 Acute Hepatitis A Non-Reactive Non-Reactive Hepatitis B Non-Reactive Non-Reactive CNV Inf. Non-Reactive Non-Reactive Rubella Infection Non-Reactive Non-Reactive Pregnancy Non-Reactive Non-Reactive Dialysis Non-Reactive Non-Reactive HAMA positive Non-Reactive Non-Reactive Interference of interfering substances Interfering substances specimens Results Monoclonal IgG 2 Non-Reactive Lipemic 7 Non-Reactive Bilirubin 2 Non-Reactive RF 3 Non-Reactive ANA 1 Non-Reactive Hemolytic 4 Non-Reactive β-hcg 4 Non-Reactive This ELISA kit is suitable for plasma samples treated with Heparin, EDTA, and Citrate trisodium. KA / 16

14 Flow chart of the test procedure Add 100 µl of Controls (3 X NC, 2 X PC) and 100 µl per Specimen into wells. Reserve 1 well for blank. Incubate the plate at 37 ± 1 C for 60 minutes. Wash the plate. (Prepare diluted conjugate in advance.) Add 100 µl of diluted conjugate to each well except the blank. Incubate the plate at 37 ± 1 C for 30 minutes. Wash the plate. Mix the TMB Substrate Solution A and B by the equal volume. Add 100 µl of the mixed substrate solution to wells. Add 50 µl of TMB Substrate Solution A to wells and then add 50 µl of TMB Substrate Solution B. Carefully mix well. Incubate at 37 ± 1 C for 15 minutes. Add 100 µl of 1 N H 2 SO 4 into each well. Determine absorbance using 450 nm as reading wavelength with nm reference wavelength 4 KA / 16

15 Resources References 1. Dienstag JL. (1983) Non-Am Non-B, hepatitis, I. Recognition, epidemiology, and clinical features. Gastroenterology85: Alter HJ. (1988) Transfusion-associated non-a, non-b hepatitis: the first decade, p In Zuckerman A.J.(ed), Viral hepatitis and liver disease. Alan R. Liss, Inc., New York. 3. Tabor E., Seeff L.B, and Gerety RJ. (1980) Chronic non-a, non-b hepatitis carrier state: Transmissible agent documented in open patient over a six-year period. N. Engl. Med. 303: Choo QL., Kuo G, Weiner AJ. Et al., (1989) Isolation of a cdna clone derived from a blood-borne non-a, non-b virus hepatitis genome. Science. 244: Dawson GJ, Lesniewski RR, and Peterson DA. (1990)Detection of Antibodies to Hepatitis C Virus in U.S. Blood Donor. J. of Clinical Microbiology, Mar. 1991, p Kuog G, Choo QL, Alter HJ, et al., (1989) An assay for circulating antibodies to a major etiologic virus of human non-a, non-b hepatitis. Science, 244: Abe K, Inchauspe G, Shikata T, and Prince AM. (1992) Three different patterns of hepatitis C virus infection on chimpanzees. Hepatology: 15: Claeys H, Volckaerts A, De Beenhouwer H, Vermtlen C. (1992) Association of hepatitis C virus carrier state with the occurrence of hepatitis C virus core antibodies. J. Med. Virol. 36: Beach MJ, et al., (1992) Temporal relationship of hepatitis C virus RNA and antibody responses following experimental infection of chimpanzee. J. Med. Virol. 36: Tsutsumt M, Urashima S, Takada A, Date T, and Tanaka T. (1994) Detection of antigen related to hepatitis C virus RNA encoding the NS5 region in the levers of patients with chronic type C hepatitis. Hepatology, 19: McFarlane IG, Smith HM, Johnson PJ, Bray GP, Vergani D, and Williams R. (1990) Hepatitis C antibodies in chronic active hepatitis: pathogenic factor or false positive result? Lancet, 335: Dow BC, Follelt EAC, Jordan T, McOmish F, Davidsion J, Gillon J, Yap PL, and Simmonds P. (1994) Lancet, 343: Uyttendaele S, Claeys H, Mertens W, Verhaet H, Vermylen C. (1994) Evaluation of third-generation screening and confirmatory assays for HCV antibodies. Vox Sang, 66: KA / 16

16 Plate Layout A B C D E F G H KA / 16