No results


      Already registered?
      If you are a registered user, please enter your email and password

      Invalid email or password



      Create your account so you can check out faster, save multiple shipping addresses and more.


      Enter your email and we will send you instructions...

      Ask the Expert

      Get Answers to Your Questions!


      Your Questions

      How thick must be the tissue section for applying IHC?

      The SenTraGor™ Immunohistochemistry Protocol has been standardized using 4.5 μm tissue sections. If you would like to use thicker tissue sections you need to optimize the protocol and increas incubation times for the SenTraGor™ compound and the antibodies.

      I am interested in combining SenTraGor™ staining with 3 other protein markers. Detection will be achieved with IF. However, this requires several antigen retrieval steps, pH6 MW treatment. How will this affect levels of lipofuscin? Do you recommend to stain with SenTraGor™ reagent as the last step before mounting?

      For co-IHC staining SenTraGor™ reagent must be applied at the end of the process after the antigen retrieval step (see co-IHC SenTraGor™ Protocol).

      So, for staining with 3 different antibodies you must follow the same tactic and apply SenTraGor™ reagent at the end of the staining protocol.

      !Notice!: before the application of SenTraGor™ reagent you must incubate tissue with sequential solutions of 50% EthOH and 70% EthOH (see steps 3.6 and 3.7 in IHC SenTraGor™ Protocol).

      What primary and secondary antibodies you recommend and have tested? And what DAB system have you tested with your reagent? Have you tested HRP substrates from VectorLab?

      In the publication of the discovery of SenTraGor™ compound, Aging Cell (2017), Supporting Information S2, there are information on the exact reagents used for the validation and development of SenTraGor™ reagent. The primary anti-biotin antibody used in all the applications is from Abcam, product code ab201341. For IHC and ICC, the inventors are using the Ultravision Quanto Detection System HRP DAB kit, ThermoFisher Scientific, catalog # TL-125-QHD, which includes its own secondary antibodies. For IF and Flow Cytometry analysis, the inventors use the secondary fluorescently labeled antibody from ThermoFisher Scientific, catalog # A-11004. We have not used so far the HRP substrates from VectorLab, but someone can use SenTraGor™ with the reagents that have been standardized in the lab.

      Can you please provide details of the primary anti-biotin and secondary fluorescent antibody used in validation of this reagent for flow cytometry?

      As indicated in the publication on Aging Cell (2017), in Supporting Information S2, the anti-biotin antibody used for validation of SenTraGor™ reagent in all its applications is from Abcam, product code ab201341. The secondary fluorescently labeled antibody that was used for the SenTraGor™ Flow Cytometry Protocol is from ThermoFisher Scientific, catalog # A-11004.

      Can I use a fluorescent conjugated Streptavidin secondary antibody?

      In theory you could use a secondary fluorescent antibody streptavidin conjugated. But from our experience the direct method doesn't work. You need the primary anti-biotin antibody to enhance the signal of SenTraGor™ reagent and then proceed with a secondary antibody against your primary antibody.

      Have you stained bone marrow sections with SenTraGor™ reagent?

      We stain routinely megakaryocytes in bone marrow samples with SenTraGor™ reagent. Actually such samples are provided as positive controls with the reagent.

      How the anti-biotin antibody can be applied on animals with endogenous biotin?

      To use the anti-biotin antibody in tissue samples with endogenous biotin you will need to block the endogenous biotin. Before applying SenTraGor™ reagent you will have to use a Streptavidin/Biotin blocking kit. Follow the instructions on SenTraGor™ Immunohistochemistry Protocol, Note 4.7.

      What would be the best positive control to use with SenTraGor™ reagent?

      The cellular systems that can be used as positive controls for staining with SenTraGor™ reagent are cells undegoing replicative senescence or cells exhibiting Stress Induced Senescence.

      Animal tissues that can be used as positive controls for staining with SenTraGor™ reagent are the animal models and human clinical cases with established senescence. For example: K-RAS induced mouse lung adenomas, irradiated human laryngeal lesions, histological sections from bone marrow that include diffusely distributed normal megakaryocytes that undergo a senescence process during their differentiation.

      You can also advise the Datasheet of the reagent.

      Would it be possible to use SenTraGor™ reagent in powder, crushed from tissue?

      The method for using SenTraGor™ reagent in powdered-crushed tissue or solutions is under development and soon it will be available under SenTraGor™ Protocols.

      Can I also test SenTraGor™ reagent on canine and feline samples?

      Yes. SenTraGor™ reagent is a chemical compound and not an antibody. It is not species specific. It is chemically attached to lipofuscin inside senescent cells from any origine.

      We failed to detect any sign of senescence using SenTraGor™ reagent.

      You need to check one of the following steps to make sure of technical correctness.

      1. After staining with SenTraGor™ use an anti-biotin antibody to enhance the signal
      2. If you are using a new anti-biotin antibody in the Laboratory, you will have to standardize its dilution. Indicated dilutions are 1/300 - 1/500
      3. Incubate the primary anti-biotin antibody overnight at 4ºC in a humidified chamber
      4. Increase the incubation time of SenTraGor™ reagent
      5. Incubate SenTraGor reagent in 37ºC in a humidified chamber for indicated time

      Is SenTraGor™ reagent compatible with frozen sections?

      Yes, SenTraGor™ reagent can be applied to frozen sections.

      If preservation of morphology is not crucial you can proceed with the Immunocytochemistry SenTraGor™ Protocol from step 3.1

      If preservation of morphology is essential, material can be fixed in 1% (w/v) formaldehyde/PBS for 5 min, then 3x washings (approx. for 1 min each) in PBS and stained by continuing the Immunohistochemistry SenTraGor™ Protocol from step 3.3

      In Immunohistochemistry, instead of using the anti-biotin antibody can you just incubate with HRP-streptavidin?

      Theoreticaly you can use directly HRP-streptavidin. But from our experience the results are more reproducible, specific and consistent when you use the anti-biotin antibody. The signal of the SenTraGor™ reagent is enhanced with the primary anti-biotin antibody and secondary antibody against the primary antibody.

      Can we apply SenTraGor™ reagent to living cells?

      No. SenTraGor™ reagent can only be applied to fixed biological material. The reagent must be diluted in ethanol which means that any treatment of the cells with the compound will result in their death and fixation.

      What is SenTraGor™? Is it an antibody?

      SenTraGor™ reagent is a chemical compound, a biotynilated Sudan Black B analogue, for the detection of lipofuscin inside senescent cells. It is not an antibody, but you need an anti-biotin antibody to enhance the signal of SenTraGor™ staining.