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Description
Human eIF4E ELISA KitProduct Specification Usage Required experimental equipment: 1. Microplate reader (450nm) 2. High precision pipettes and pipette tips: 0. 5 10uL, 5 50uL, 20 200uL, 200 1000uL 3. 37C incubator 4. Distilled or deionized water Sample preparation and requirements: Tissue homogenization: Rinse the tissue with pre chilled PBS (0. 01M, pH 7. 4) to remove residual blood (lysed red blood cells in the homogenate will affect the measurement results). Weigh and
Product Specification
| Usage | Required experimental equipment: 1. Microplate reader (450nm) 2. High-precision pipettes and pipette tips: 0.5-10uL, 5-50uL, 20-200uL, 200-1000uL 3. 37°C incubator 4. Distilled or deionized water Sample preparation and requirements: Tissue homogenization: Rinse the tissue with pre-chilled PBS (0.01M, pH 7.4) to remove residual blood (lysed red blood cells in the homogenate will affect the measurement results). Weigh and mince the tissue. Add the minced tissue to the appropriate volume of PBS (generally a 1:9 weight-to-volume ratio, e.g., 1g of tissue sample to 9mL of PBS. The specific volume can be adjusted according to experimental needs and recorded. It is recommended to add protease inhibitors to the PBS) in a glass homogenizer and grind thoroughly on ice. To further lyse tissue cells, the homogenate can be sonicated or repeatedly frozen and thawed. Finally, centrifuge the homogenate at 5000×g for 5-10 minutes, and collect the supernatant for analysis. Cell Lysis Buffer: Adherent cells should be gently washed with pre-chilled PBS, then trypsinized and harvested by centrifugation at 1000×g for 5 minutes. Suspension cells can be harvested directly by centrifugation. Collected cells should be washed three times with pre-chilled PBS and resuspended in 150-200 μL of PBS per 1×10^6 cells (it is recommended to add protease inhibitors to the PBS; if the cell count is very low, reduce the PBS volume appropriately). Disrupt the cells by repeated freezing and thawing or sonication. Centrifuge the extract at 1500×g for 10 minutes at 2-8°C, and collect the supernatant for analysis. Other biological fluids: Centrifuge at 1000xg for 20 minutes, remove the supernatant, and test. Pre-test preparation: 1. Remove the test kit from the refrigerator 10 minutes in advance and equilibrate to room temperature. 2. Prepare the standard gradient working solution: Add 1 mL of universal diluent to the lyophilized standard, let it stand for 15 minutes to completely dissolve, then gently mix (concentration is 20 ng/mL). Then dilute to the following concentrations: 20 ng/mL, 10 ng/mL, 5 ng/mL, 2.5 ng/mL, 1.25 ng/mL, 0.625 ng/mL, 0.3125 ng/mL, and 0 ng/mL. Serial dilution method: Take 7 EP tubes and add 500 μL of universal diluent to each tube. Pipette 500 μL of the 20 ng/mL standard working solution into the first EP tube and mix thoroughly to make a 10 ng/mL standard working solution. Repeat this procedure for subsequent tubes. The last tube serves directly as a blank well; there is no need to aspirate the liquid from the penultimate tube. See the figure below for details. 3. Preparation of Biotinylated Antibody Working Solution: 15 minutes before use, centrifuge the concentrated biotinylated antibody at 1000×g for 1 minute. Dilute the 100× concentrated biotinylated antibody to a 1× working concentration using universal diluent (e.g., 10µL concentrate + 990µL universal diluent). Prepare immediately before use. 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 a capture antibody against eukaryotic initiation factor-4A (eIF4E). After incubation and washing, the sample is developed using the substrate TMB. TMB is converted to blue by peroxidase (HRP) catalysis and to yellow by acid. The intensity of the color is positively correlated with the amount of eukaryotic initiation factor-4A (eIF4E) in the sample. The absorbance (OD) is measured at 450 nm using a microplate reader to calculate the sample concentration. | |||||||||||||||||||||||||||||||||
| Source | Human | |||||||||||||||||||||||||||||||||
| Synonym | Human eukaryotic initiation factor-4A ELISA Kit | |||||||||||||||||||||||||||||||||
| Detection Type | Double antibody sandwich method | |||||||||||||||||||||||||||||||||
| Composition |
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| Background | Eukaryotic initiation factor 4E (eIF4E) is a protein encoded by the eIF4E gene. It is involved in directing the ribosome to the cap structure of the mRNA. It is a 24 kDa polypeptide that exists both in its free form and as part of the eIF4F preinitiation complex. Almost all cellular mRNAs require eIF4E for protein translation. The eIF4E polypeptide is the rate-limiting component of the eukaryotic translation machinery and is involved in the mRNA-ribosome binding step of eukaryotic protein synthesis. | |||||||||||||||||||||||||||||||||
| 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 | 0.312-20 ng/mL | |||||||||||||||||||||||||||||||||
| Applications | Tissue homogenates, cell lysates, and other biological fluids |
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4.4 ★★★★★
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Product Reviews
★★★★★ 5
Excellent fan, moves a lot of air a long distance, and is very quiet
Color: White, Size: 42 inches
We have the other type of Levoit standing fan which is super quiet and moves air nicely inside a room. But we have one side of the house that gets little air flow in general, so we bought this to try and improve the air flow around the house by directing air from one side to the other. We have been using a Vornado fan for this in the past, but the air flow it produces dissipates too quickly and the damn thing sounds like a small jet engine.
So as we had such a great experience with the other Levoit fan we tried this one. It is very expensive, and there are cheaper ones available, however we felt that longer distance airflow and quiet were very important to us.
We are not disappointed. This fan is really quiet, on lower settings it is whisper quiet, perfect for moving air and still being able to work, or be in a video call. On the highest setting it does make some noise, air moving quickly produces turbulence, there is no way to avoid it. But the noise level is low, and not very noticeable. However it moves huge amounts of air, an directs it very tightly. It does not dissipate even after 30-40ft. Great for moving air around a house.
On the down side, it only has 5 speeds, and it only rotates 90 degrees. The other Levoit fan has more options to control the air flow. It displays the temperature but only when changing the settings. It would be nice to have a button on the remote to display temp, even if just briefly. The auto program has no hysteresis when changing fan speeds, so when the temp hits a point where it is going to change, it keeps speeding up and slowing down every second or two. With that the noise becomes noticeable for a while. A 20 second or so hysteresis delay would solve that issue.
On the major up side, it is as quiet as advertised, it blows huge amounts of air, even on the lowest setting it moves enough air to slowly flap paper 50ft away, and you cannot hear it. The remote is good, and there is a little nook to store it in. You can have it set to not display anything, so it stays dark at night, the timer works well, although we find we don't use it. It is very easy to open and clean.
In short, even though it cost a premium price it ended up being worth it, and now is in use 24/7. Would definitely by again if we needed another one.
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Reviewed in the United States on September 24, 2025
★★★★★ 5
“Excellent purchase for summer ☀️❄️”
Color: White, Size: 36 inches, Color: White, Size: 36 inches
I bought this 36-inch Levoit tower fan and it far exceeded my expectations. I love that it has a quiet mode, especially the night mode, because it allows me to sleep peacefully without disturbing noises. It cools the room very well, and the airflow is constant and pleasant. I also like that it has several speeds and modes, which allows me to adjust it according to the day's temperature.
What I liked most was the design. I love it! It's a super modern tower fan that doesn't take up much space, so it looks good in any corner of the house. The remote control makes it even more practical, since I can use it without getting up.
In short, it's an efficient and practical fan, perfect for everyday use. I definitely recommend it if you're looking for a quiet yet powerful fan.
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Reviewed in the United States on May 26, 2026
★★★★★ 5
Best fan I have ever used.
Color: White, Size: 42 inches Wifi
Easy assembly, simple WiFi and Alexa connection. Extremely quiet operation. Fan speeds and oscillating feature are perfect.
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Reviewed in the United States on May 15, 2026
★★★★★ 5
It has many conveniences
Color: White, Size: 42 inches, Color: White, Size: 42 inches
I like that it detects temperature and determines what fan speed it should be on to control temperature in the room. Its made a notable difference in my warmest room of the house this summer. Its nice and quiet. You can also adjust the blades up or down if you want to redirect the air flow much like in a vehicle. I got the taller fan for the bigger living space i have and it’s comfortable. I feel the air right away. It’s bot like a pedestal fan. This is much more giving to the entire body rather than just the face. It’s also not as intrusive as a pedestal fan. It fits in smaller spaces. It doesn’t block the view like a pedestal fan
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Reviewed in the United States on July 22, 2025
★★★★★ 5
Liked this so much that I purchased a second one for another room
Color: White, Size: 36 inches
I liked this fan so much that I purchased a second one for another room. Works well, has 5 different speeds, several functions and setting. Has a remote control and a space on the fan that holds the remote. I was initially torn between this fan and another brand, but chose this one because it can be easily taken apart for cleaning. Also it is a very good value for the cost. It is not silent, but it is not loud at all. The fan is very sturdy and easy to assemble. The only assembly is a giant plastic nut on the bottom that holds the stand in place. IMO if you choose this fan, you will not be disappointed.
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Reviewed in the United States on May 20, 2026