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Description
Rat HE4 ELISA KitProduct Specification Usage Experimental equipment required for the experiment: 1. Microplate reader (450nm) 2. High precision pipette and gun tips: 0. 5 10uL, 5 50uL, 20 200uL, 200 1000uL 3. 37 constant temperature box 4. Distilled water or deionized water Sample processing and requirements: Serum: Place the whole blood sample collected in the serum separation tube at room temperature for 2 hours or at 4 overnight, then centrifuge at 1000g for 20
Product Specification
| Usage |
Experimental equipment required for the experiment: 1. Microplate reader (450nm) 2. High-precision pipette and gun tips: 0.5-10uL, 5-50uL, 20-200uL, 200-1000uL 3. 37℃ constant temperature box 4. Distilled water or deionized water Sample processing and requirements: Serum: Place the whole blood sample collected in the serum separation tube at room temperature for 2 hours or at 4℃ overnight, then centrifuge at 1000×g for 20 minutes, and take the supernatant, or store the supernatant at -20℃ or -80℃, but avoid repeated freezing and thawing. Plasma: Collect specimens using EDTA or heparin as an anticoagulant and centrifuge at 1000×g for 15 minutes at 2-8°C within 30 minutes of collection. Remove the supernatant for testing, or store at -20°C or -80°C, but avoid repeated freezing and thawing. Cell culture supernatant: Centrifuge at 1000×g for 20 minutes. Remove the supernatant for testing, or store at -20°C or -80°C, but avoid repeated freezing and thawing. Pre-Test Preparation: 1. Remove the test kit from the refrigerator 10 minutes in advance and equilibrate to room temperature. 2. Prepare a gradient standard working solution: Add 1 mL of universal diluent to the lyophilized standard. Let stand for 15 minutes to completely dissolve, then gently mix (concentration 10 ng/mL). Then dilute to the following concentrations: 10 ng/mL, 5 ng/mL, 2.5 ng/mL, 1.25 ng/mL, 0.625 ng/mL, 0.3125 ng/mL, 0.15625 ng/mL, and 0 ng/mL. Serial dilution method: Take seven EP tubes and add 500 μL of universal diluent to each tube. Pipette 500 μL of the 10 ng/mL standard working solution into the first EP tube and mix thoroughly to make a 5 ng/mL standard working solution. Repeat this procedure for subsequent tubes. The last tube serves as a blank well; there is no need to pipette liquid from the penultimate tube. See the figure below for details. 3. Preparation of biotinylated detection antibody working solution: Centrifuge the concentrated biotinylated antibody at 1000×g for 1 minute 15 minutes before use. Dilute the 100× concentrated biotinylated antibody to a 1× working concentration with universal diluent (e.g., 10uL concentrate + 990uL universal diluent). Prepare and use immediately. 4. Prepare the enzyme conjugate working solution: 15 minutes before use, centrifuge the 100× concentrated enzyme conjugate at 1000×g for 1 minute. Dilute the 100× concentrated HRP enzyme conjugate to a 1× working concentration with universal diluent (e.g., 10 μL of concentrate + 990 μL of universal diluent). Prepare immediately. 5. Prepare the 1× wash solution: Dispense 10 mL of 20× wash solution into 190 mL of distilled water (concentrated wash solution removed from the refrigerator may crystallize; this is normal. Allow to stand at room temperature until the crystals have completely dissolved before preparing). Procedure: 1. Remove the desired strips from the aluminum foil bag after equilibration at room temperature for 10 minutes. Seal the remaining strips in a ziplock bag and return to 4°C. 2. Sample addition: Add 100 μL of sample or standard of varying concentrations to the corresponding wells. Add 100 μL of universal diluent to the blank wells. Cover with a film and incubate at 37°C for 60 minutes. (Recommendation: Dilute the sample to be tested at least 1-fold with universal diluent before adding it to the ELISA plate. This will reduce the impact of matrix effects on the test results. The sample concentration should be multiplied by the corresponding dilution factor when calculating the final sample concentration. It is recommended to run replicates for all test samples and standards.) 3. Add Biotinylated Antibody: Remove the ELISA plate and discard the liquid without washing. Add 100 μL of Biotinylated Antibody Working Solution directly to each well. Cover with a film and incubate at 37°C for 60 minutes. 4. Wash: Discard the liquid and add 300 μL of 1x Wash Solution to each well. Let stand for 1 minute, shake off the wash solution, and pat dry on absorbent paper. Repeat this process three times (a plate washer can also be used). 5. Add Enzyme Conjugate Working Solution: Add 100 μL of Enzyme Conjugate Working Solution to each well. Cover with a film and incubate at 37°C for 30 minutes. 6. Washing: Discard the liquid and wash the plate five times as in step 4. 7. Adding substrate: Add 90 μL of substrate (TMB) to each well, cover with a sealing film, and incubate at 37°C in the dark for 15 minutes. 8. Adding stop solution: Remove the ELISA plate and add 50 μL of stop solution directly to each well. Immediately measure the OD value of each well at a wavelength of 450 nm. Calculating experimental results: 1. Calculate the average OD value of the standard and sample replicates and subtract the OD value of the blank well as a correction factor. Plot the standard curve of the four-parameter logistic function on double-logarithmic graph paper, with concentration as the horizontal axis and OD value as the vertical axis. 2. If the sample OD value is higher than the upper limit of the standard curve, dilute the sample appropriately and retest. Multiply the sample concentration by the corresponding dilution factor. |
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| Theory | This kit uses a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA). Sample, standard, biotin-labeled detection antibody, and HRP conjugate are sequentially added to microwells pre-coated with an Epididymal Protein 4 (HE4) capture antibody. After incubation and washing, the sample is developed using the substrate TMB. TMB is converted to blue by HRP peroxidase and to yellow by acid. The intensity of the color is positively correlated with the amount of Epididymal Protein 4 (HE4) in the sample. The absorbance (OD) is measured at 450 nm using a microplate reader to calculate the sample concentration. | |||||||||||||||||||||||||||||||||
| Source | Rat | |||||||||||||||||||||||||||||||||
| Synonym | Rat Epididymal Protein 4 ELISA Kit | |||||||||||||||||||||||||||||||||
| Detection Type | Double antibody sandwich method | |||||||||||||||||||||||||||||||||
| Composition |
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| Background | HE4 is a protein encoded by the WFDC2 gene. It is a tumor marker for ovarian cancer, with a sensitivity of 80% at a cutoff of 150 pmol/L. It is a member of the WFDC domain family. The WFDC domain, also known as the WAP signature motif, contains eight cysteines that form four disulfide bonds in the protein's core, acting as a protease inhibitor in many family members. This gene is expressed in lung epithelial cells and has also been found in some ovarian cancers. The encoded protein is a small secreted protein. | |||||||||||||||||||||||||||||||||
| General Notes | 1. Strictly adhere to the specified incubation time and temperature to ensure accurate results. All reagents must be at room temperature (20-25°C) before use. Refrigerate reagents immediately after use. 2. Improper plate washing may result in inaccurate results. Ensure that all liquid in the wells is aspirated thoroughly before adding substrate. Do not allow the wells to dry out during incubation. 3. Remove any residual liquid and fingerprints from the bottom of the plate, as this will affect the OD value. 4. The substrate developer solution should be colorless or very light in color. Do not use substrate solution that has turned blue. 5. Avoid cross-contamination of reagents and specimens to prevent erroneous results. 6. Avoid direct exposure to strong light during storage and incubation. 7. Do not expose any reagents to bleaching solvents or the strong fumes emitted by bleaching solvents. Any bleaching agent will destroy the biological activity of the reagents in the kit. 8. Do not use expired products, and do not mix components with different product numbers and batches. 9. Recombinant proteins from sources other than the kit may not be compatible with the antibodies in this kit and will not be recognized. 10. If there is a possibility of disease transmission, all samples should be managed properly and samples and testing devices should be handled according to prescribed procedures. |
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| Storage Temp. | If the unopened kit is stored at 4°C, the shelf life is 6 months. | |||||||||||||||||||||||||||||||||
| Test Range | 0.156-10 ng/mL | |||||||||||||||||||||||||||||||||
| Applications | Serum, plasma, cell culture supernatant |
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4.3 ★★★★★
Based on 27 reviews
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Product Reviews
★★★★★ 5
Good Food
Flavor Name: Traditional, Size: 4 Ounce (Pack of 1)
I have had South African Billtong before and I loved it, so I thought I would try SA Droewars and see if they were as satisfying. The answer is yes! They are delicious and nothing like your typical mass marketed jerky snacks sold in the US. Droewars are lightly seasoned beef jerky sticks and, although I have not seen the numbers, they seem to be only lightly salted (important for me). The meat is not chewy or grisly, so the beef cuts they use must be prime.
This is the first time I have tried the Ayoba-Yo brand and I am happy with my purchase. I am awaiting delivery of several varieties of Billtong from Ayoba-Yo presently and I will report back.
Not inexpensive, but the value is there for sure.
Jimmy
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 17, 2019
★★★★★ 1
Almost not edible
Flavor Name: Traditional, Size: 2 Ounce (Pack of 3), Flavor Name: Traditional, Size: 2 Ounce (Pack of 3)
I am south african, an afrikaaner. I grew up eating droewors and biltong. I'm not sure what went wrong with this product. I have to believe it was off quality product and not what they are choosing to ship. The flavor was ok. Nothing spectacular. Thr big issue was texture of the droewors and the fact that the meat had shrunk away from the casing leaving the casing inedible. See my pic. This is not what droeworse looks like. Also, being from south africa I've never heard anyone say the word ayoba....
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Reviewed in the United States on July 28, 2023
★★★★★ 4
Good taste. A bit dry texture.
Flavor Name: Traditional, Size: 4 Ounce (Pack of 1)
Great taste. Unusual flavor but still good. It was a very dry texture. I do want to try another flavor.
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Reviewed in the United States on September 19, 2025
★★★★★ 3
Meh
Flavor Name: Traditional, Size: 2 Ounce (Pack of 3)
It’s just okay. I’ve been looking for something that is as close to possible as dry wors in South Africa. This is not it. Is it dry wors? Yes. But is it good dry wors? No; it is very average. I wouldn’t buy it again. I’ll have to keep on searching for that yummy, moist, soft, flavorful dry wors that seems so elusive on this side of the pond.
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Reviewed in the United States on May 13, 2026
★★★★★ 5
Droewors + WHY BARS
Flavor Name: Traditional, Size: 1 Ounce (Pack of 12)
I like them as they are a quick snack on the go. I go for these beef sticks and I eat lots of tasty WHY BARS to get high-quality nutrition for my busy lifestyle. Why not!
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Reviewed in the United States on August 25, 2025