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TUNEL Apoptosis Detection Kit(Biotin labeled POD) (Frozen section)
$695.00 / 50T
  •  1.TUNEL principle
    TUNEL apoptosis detection kit is to use the non-isotopic method to detect DNA fragmentation
    during cell apoptosis, can quickly and accurately detect single apoptotic cells in place.The prin-
    ciple is when apoptosis occurs, endogenous nuclease be activated, making DNA double-
    strand breaks or a chain appearing breach, produce a series of 3'-OH ends. Under the action
    of the enzyme (TdT), the tissue cells in situ DNA incision can be labeled with biotin-dUTP,
    TUNEL (Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling), specific
    binding with Streptavidin-HRP. In the presence of the horseradish peroxidase substrate
    diaminobenzidine (DAB),which displayed as brown (peroxidase activity), specificity accurately
    positioned apoptotic cells.With ordinary microscope ,can observation and counting the apoptotic

    cells.Beause there are almost no cleavage of DNA in proliferating cells and normal cells, thus
    no 3'-OH formed, and can seldom be dyed.


    A kit
    DNase(50 U/µl)
    1.0 ml
    1.0 ml
    Equilibration Buffer
    1.0 ml
    2.5 ml
    5.0 ml
    TdT Enzyme
    B kit
    Avoid light
    DAB-A Solution
    DAB-B Solution
    DAB-C Solution






             3.Materials Required preparetion
    Paraformaldehyde1×PBS pH 7.4H2O2Triton X-100Methanol, hematoxylin dye, coverslips, staining jar, Incubator, measuring cylinder
    4.Assay Procedure
    Before the experiment, ready for the corresponding reagents and apparatus, please prepare the next step work solution during each step reaction or dipping.Please mark the samples with immunohistochemistry pen, add two sample sections used for the positive and negative separately well marked.
       1) Fixed
    Preparation of 4% paraformaldehyde fixation, for example: 4g paraformaldehyde with 1 × 
             PBS dissolved and set the volume to 100 ml (paraformaldehyde insoluble, with HCl to
             adjust pH up paraformaldehyde dissolved)

        √ Please immersing the frozen slices into dyeing container containing 4% paraformaldehyde
             fixative dyeing, at room temperature (15-25 ° C) fixed 20min;

        √ Immersed the Slice into 1 × PBS rinsed twice, 5min each;
       2) Transparent
        √ Preparation 1% Triton X-100 transparent liquid,for example: 99ml 1 × PBS add 1.0ml

              Triton X-100, mixing,
        √ Immersed slice into the transparent liquid, penetration at room temperature for 3-5min;
        √ Immersed slice into1×PBSrinsed three, 5min each;
       3) Close
        √ Preparation 3%H2O2 blocking solution; for example: 80ml methanol was added to 10m
              H2O and 10ml H2O2 (30%);

        √ Immersed slice into blocking solution, at room temperature15-25℃)for 10min;
        √ Immersed slice into 1×PBSrinsed three, 5min each;
       4) Prepare positive film
        √ Prepare 100μl DNasereaction solution containing 2000 U ~ 3000 U, method as follows:
              ►2000 U: 40μl DNase
    (50 U / μl) plus 60μl DNaseBuffer
              ►3000 U: 60μl DNase
    (50 U / μl) plus 40μl DNaseBuffer
        √ Dropping 100μl above DNasereaction solution to positive sample slices ,at room tem-
              perature ~ 37
    for 10 ~ 30min,
        √ Immersed slice into 1×PBSrinsed three, 5min each;
        5) connection
    Preparation TdT enzyme reaction solution: Calculate the number of samples then prepa-
              ration (negative is not included), the amount for each sample: added 1.0μl Biotin-11-dUTP
    4.0µl TdT Enzymeto 45μl Equilibration Buffer, and 4.0μl TdT Enzyme
        √ Please dry the samples around with absorbent paper, dropping 50μlTdT enzyme reaction
              solution for each sample, add coverslip ,then placed into Incubator at 37 °C avoiding light
              reaction 60min (Note: negative control samples without TdT enzyme reaction solution;
    Immersed slice into 1×PBSrinsed three, 5min each; ransportation and Storage
         6) Label
        √ Preparation the working solution of Streptavidin-HRP, Calculate the number of samples
             then preparation, the amount for each sample is: add 0.5μl Streptavidin-HRP to 49.5μl 1 ×
             PBS, avoiding light;

        √ Please dry the samples around with absorbent paperdropping50µlStreptavidin-HRP
             reaction solution for each sample,add coverslip ,then placed into Incubator at 37 °C avoid-
             ing light reaction 30min
    Immersed slice into 1×PBSrinsed three, 5min each;
        7) Color Developing
       √ Preparation DAB reaction solution:Calculate the number of samples then preparation,add
            2.5µl D
    AB -A Solution to 50 µl dH2O for each sample, fully mixed,then add 2.5 µl DAB-B
            Solution and 2.5µl DAB-C Solution
       √ Please dry the samples around with absorbent paperdropping50µl DABreaction
    ,color reaction at Room temperature for 30s5min;
       √ Immersed slice into 1×PBSrinsed three, 5min each;Observed under the microscope, 
        8) Re-dyeing
            Hematoxylin, methyl green conventional dye-stained (optional step)
            The sample was dropped on hematoxylin , dyeing 30s ~ 5min (please observed under the 
            microscope),then immersed in 1% hydrochloric acid methanol solution after rinsed with
            distilled water to differentiation 5S, claim washed with distilled water. Respectively, with
            70%, 85%, 95%, 100% ethanol immersion 5min.Then dip twice with xylene, each 10min. 
            Dry slices, plus neutral gum, plus coverslip, observed under an optical microscope,
    5.Transportation and Storage Conditions
    Please transportation at 2-8 ;A kit components stored at -20 , B-kit components at 2-8
    avoid light, the shelf life is one year.

         1) The best reaction solution volume should be prepared for one time according to the number
             of samples, and then dropped at each sample, avoiding reagents loss. 

         2) For short-term preservation of TdT enzyme reaction liquid, please placed on ice.
         3) The prepared DAB working solution should be light brown, if the color is too deep, please do
              not use.

         4) Please wear gloves to prevent reagent contamination skin.If contamination,please flush with
             water immediately.

  • 1. How do I place an order from outside of China?

    You can purchase directly from us. Please send us a formal purchase order (PO) and send your order to

    2. What information is needed when placing an offline order?

    Company/Institute Letter Head Purchase Order Number
    Recipient Full Name
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    3. How do I request a quote for a bulk quantity of product?

    To receive a quote, please contact us at Please indicate the quantity of the product you want to purchase in your email. The quote will be sent to you within one business day.

    4. Can I get a discount?

    We only offer discount to those who make bulk purchases. For bulk quotation, please contact us by email: Please indicate the approximate quantity of the product you want to purchase in your email.

    5. What is a "Purchase Order Number"?

    A purchase order number is generated by the buying institution. It indicates that the requester is authorized to purchase the products.

    6. How do I search for products?

    To search for a product of interest, simply type the product name or Catalog number in the search box on the top of your screen. If you cannot find the product you need, please contact us by email: . We can search our database of products that are still under development.

    7. Can I track a shipped order?

    The tracking number will be sent to you via email when it is available. You can check the delivery status .

    8. How can I pay for my order?

    For orders, the acceptable payment methods include PayPal, wire transfer and check. For details, please see .

    9. Should I prepay for the orders?

    If it is your first order from our company, we prefer a full up-front payment. Client account number will be set up for new customers. Our regular clients are allowed to pay for it before we shipped it for you.

    10. What is the shipping condition of the products?

    ELISA kits, and antibodies are all shipped at ambient temperature. whereas antibodies are provided as liquid. They are shipped out with ice unless customers require otherwise.

    11. Are antibodies from BMASSAY stable for delivery at RT?

    We have tested the stability and the bioactivity of antibodies remained at -20℃, room temperature and 37℃ for 7 days. The results indicated that the stability and the bioactivity of the antibodies remained at room temperature and 37℃ are the same as those remained at -20℃. In additional, we have never received any complaints about the bioactivity of our products from our regular customers.

    12. How do l cancel an order?

    To cancel an order, please contact us via or call 010-59871930. For orders that were already shipped, The customer is responsible for paying for the return shipping cost.

    13. What if I receive a wrong item?

    If an error by BMASSAY results in shipment of an incorrect order, BMASSAY will either ship a replacement order at no charge or credit your account with the full purchase price. If an error by a customer results in the shipment of an incorrect order and is reported to BMASSAY. within ten (10) days, you may obtain a Return Authorization. The customer is responsible for paying for the return shipping cost. BMASSAY will not refund, replace or accept returns of temperature sensitive goods in either case where there is Purchaser order error or incorrect storage of goods upon receipt and/or delivery to the Purchaser. We will make every effort to process your refund quickly. You will be notified of your refund by email.

    14. What if I do not receive my order within your estimated delivery time?

    Delays may occur due to conditions beyond our control, which may include situations rising from strikes, fire, arson, riots, earthquake, floods etc. You can check the status of your shipment with the tracking number emailed to you when your package is shipped. If you did not receive the tracking number, please contact us via with your order number or call us at 010-59871930 during office hours. If your package is lost before being delivered, we will ship you a replacement at no charge or credit your account with the full purchase price.

    15. What if I receive an item that is damaged?

    If you find the item has been damaged during transportation, please contact us immediately within 48 hours upon receiving the product via email or call us at 010-59871930 during office hours.

    Technical FAQ

    16. Why are protectants added to protein solutions before lyophilization? What protectants do you add to your products?

    Protectants (stabilizers) are added to protect proteins during lyophilization and/or long-term storage. Proteins are subjected to various stresses generated by lyophilization which may cause loss of activity, aggregation, or denaturation. Protectants can alleviate the stresses by several mechanisms including formation of an amorphous glassy state, replacing water, hydrogen bonding to proteins, physical dilution and separation of protein molecules, etc. Common protectants/stabilizers include sugars, polyols, polymers, surfactants, as well as some proteins and amino acids. We use trehalose and mannitol (normally 8% w/v) as protectants for lyophilization. Trehalose is a non-reducing disaccharide, well-known for its ability to stabilize biomolecules and microorganisms during prolonged period of desiccation. Mannitol is also commonly used as a stabilizer as well as a bulking agent in the process of lyophilization. It was reported to reduce aggregation for some proteins during lyophilization.

    17. How to reconstitute the lyophilized powder? Should I use sterile water, PBS or other buffer?

    We recommend using sterile water for reconstitution. Add the recommended volume of sterile water of to the vial, and gently shake it to solubilize the protein completely. Do not shake violently. PBS or other buffer can also be used as reconstitution agent as the salts in PBS can be omitted when the concentration and reconstitution volume is low. If possible, we suggest you compare the results of different reconstitution agents.

    18. Why are some proteins fused to tags?

    The initial use of protein tags is for protein purification purpose. In addition, tags are also used for protein detection in several applications, such as western blot and ELISA, when the specific antibodies are not available. Furthermore, Fc tag stabilizes molecules, which may increase the half-life of the linked products. Since the Fc fragment tends to dimerize, it helps the linked protein, particularly receptors, to form biologically active dimers.

    19. Do protein tags affect protein activity?

    It is different from case to case. For some applications, small tags, such as His-tag and FLAG-tag, may not affect protein activity and do not need to be removed. For example, there are more than 100 structures of His-tagged proteins in the Protein Data Bank. This indicates that the small His-tag often do not interfere with correct protein folding. Additionally, tested activity results are listed on our protein web pages, if you have concerns about tags interfering with protein activity. If there is no activity data online and activity is crucial to your experiments, please feel free to contact us ( for latest information. For some recombinant proteins from SBI, fusion tags are removable by proteases. Please contact us for details.

    20. How should I store the products?

    Lyophilized proteins are stable for at least twelve months from date of receipt when stored at -20℃ to -70℃. Upon reconstitution, the proteins can be stored at 2℃ - 8℃ for at least 1 month without detectable loss of activity. Reconstituted protein can also be aliquoted and stored frozen at -20℃ to -70℃in a manual defrost freezer for six months without detectable loss of activity. Avoid repeated freeze-thaw cycles.

    21.How do you determine the quantity of your proteins and antibodies?

    Normally we determine the concentration of proteins and antibodies by measuring their UV absorbance. The concentration of proteins and antibodies is calculated by their extinction coefficients. We also use BCA, SDS-PAGE, HPLC and other methods to quantify the proteins and antibodies.

    22. Why is the quantification of the protein generated by my assay different from the one on the label?

    Different assays generate different quantification result. Sometimes the discrepancy can be significant if you conduct a different assay. It is also possible that the protein forms aggregations during storage which causes loss after reconstitution and centrifugation. We run quality control tests for each batch of proteins and antibodies. However, it is still inevitable that a few vials are not the same with the rest of the same batch. This happens very rare and can be minimized by our effort on Quality Control.

    23. Who should I report to if I find the product quantity is incorrect? How will you deal with this kind of complaints?

    You can call us at 010-59871930 or send us an email to We will repeat your quantification assay on the same batch of product that was sent to you. If there is a discrepancy between the two assays, we will perform more types of assays to determine the quantity. If the quantity is actually incorrect, we will make up the shortage for free and give you credits for your future orders.

    24. What materials are provided in your ELISA Kit?

    Currently our ELISA kits contain the Capture Antibody, the Detection antibody, and the Standard (recombinant protein). Other buffer solutions and Substrate stock solutions required for the development of sandwich ELISAs need to be prepared by customers.

    25. How many samples could be detected with each ELISA Kit?

    Each kit contains sufficient materials to run ELISA assays on 96-well plates (96T). If you have any other question, please see the product's Certificate of Analysis or contact us directly.

    26. How should I store BMASSAY's Antibodies?

    Specific storage recommendations are listed on the Certificate of Analysis. We recommend that all antibodies be aliquoted into smaller aliquotes and stored at -20° C or below. Avoid multiple freeze-thaw cycles as this will affect antibody activity. We cannot guarantee how the performance of the antibodies if they are not stored as stated on the datasheet.

    27. What is the shelf life of BMASSAY's antibodies?

    Unless otherwise indicated in the data sheet, most of our antibodies can be stored at 2℃-8℃ for one month without detectable loss of activity and are stable for twelve months from date of receipt when stored at -20℃ to-70℃. Repeated freezing and thawing should be avoided.

    28. How are BMASSAY's Antibodies supplied?

    All BMASSAY's antibodies are supplied as liquid. It remains stable during the delivery process at ambient temperature. We have tested every antibody's stability and activity following a period of more than 7 days at -20°C, room temperature, or 37°C. Antibodies under all three conditions turned out to be equally active and stable.

    29. Which dilutions of the antibody should I use in my experiment?

    We list a dilution suggestion on the datasheet for most of our antibodies. Please remember that these dilutions and concentration estimates are simply recommended as a starting point, and it may be necessary to adjust the dilution based on the experimental results

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