SuperBlock™ T20 (TBS) Blocking Buffer, 1 L - FAQs

View additional product information for SuperBlock™ Blocking Buffer - FAQs (37518, 37580, 37581, 37545, 37535, 37536, 37515, 37516)

22 product FAQs found

What should I do about the colloidal carbon (black precipitate) in SuperBlock Blocking Buffer solution?

Allow any colloidal carbon, if present, to settle to the bottom of the bottle and pouring off what you need to use. We do not recommend centrifugation or filtering because these procedures may reduce the product's blocking capabilities.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

What preservative is used in SuperBlock Blocking Buffer, and what is its source?

Kathon Preservative, a broad spectrum antimicrobial agent, is used at a concentration of 600 ppm.

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What is SuperBlock Blocking Buffer's shelf life?

Its shelf life is one year at 4°C.

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What incubation time and temperature should I use for effective blocking using the SuperBlock Blocking Buffer ?

Typical procedures use 1 hour at room temperature or overnight at 4°C. However, sufficient blocking in many procedures is possible in 3 x 2 minutes at room temperature.

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Is SuperBlock Blocking Buffer RNase-free?

No, SuperBlock Blocking Buffer is not RNase-free.

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Does SuperBlock Blocking Buffer work with nylon and nitrocellulose membrane?

Yes, SuperBlock Blocking Buffer works with nylon and nitrocellulose membrane.

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Does SuperBlock Blocking Buffer need to be diluted?

No. It is supplied at 1X concentration and should be used “as is.“

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Does SuperBlock Blocking Buffer contain albumin, biotin, DNA, detergent or phosphoproteins?

No. Unless it includes “T20“ in the name, for example, SuperBlock T20 (PBS) Blocking Buffer, which contains 0.05% Tween 20.

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Can plates be blocked with SuperBlock Blocking Buffer and then stored dry?

After the plates are blocked, remove the blocking buffer and air dry the plates for several hours. Store plates with desiccant in a plastic bag at 4°C. Change desiccant after 24 hours for optimal storage. The plates should be stable for at least 12 months.

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How can I reduce background bands in my Western blot?

Optimize the concentration of primary and secondary antibodies. In some cases, increasing the concentration of blocking agent (BSA or non-fat dry milk) or usiing an alternative blocking solution such as Starting Block or SuperBlock may reduce background signal. After incubation with the primary antibody, wash at least 2 times with TBST (include 0.5 M NaCl in one or more of the wash steps). Avoid Nonidet P40 or Triton X-100 in buffers because protein detection is decreased when these detergents are used.

Find additional tips, troubleshooting help, and resources within our Protein Electrophoresis and Western Blotting Support Center.

What is the concentration of protein in the SuperBlock T20 (TBS) Blocking Buffer?

This information is proprietary. The protein concentration in the SuperBlock T20 (TBS) Blocking Buffer has been optimized for direct usage without further dilution, however if desired, the blocking buffer may be diluted with phosphate-buffered saline. For best results, our recommendation is to empirically determine the optimal concentration to use.

Find additional tips, troubleshooting help, and resources within our Protein Electrophoresis and Western Blotting Support Center.

Will freezing and heating damage SuperBlock Blocking Buffers?

Generally, the Superblock Blocking Buffer formulations are tolerant of 2-3 freeze/thaw cycles. Heating above 37 degrees C for an extended period will denature the protein in the blocking buffers rendering them less effective.

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Are SuperBlock Blocking Buffers compatible with the Pierce Reversible Protein Stain Kit for PVDF Membranes (Cat. No. 24585)?

The procedure for the Reversible Protein Stain Kit for PVDF Membranes (Cat. No. 24585) is performed before the membrane is blocked with the blocking buffer, and thus, has no effect on the subsequent blocking.

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Can I use SuperBlock Blocking Buffers for dilution of my protein samples?

Yes, using the SuperBlock Blocking Buffer as a diluent can help stabilize the protein during incubations and also enhance blocking.

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Do both the powder and liquid formats of SuperBlock (TBS) Blocking Buffer have the same formulation?

Yes, besides the fact that SuperBlock (TBS) Blocking Buffer Dry Blend (Cat. No. 37545) does not contain the Kathon preservative or Tween-20 detergent, the five pouches of SuperBlock (TBS) Blocking Buffer Dry Blend (Cat. No. 37545) when reconstituted (each pouch in 200 mL Ultrapure water for 1x buffer) is equivalent to one liter of the liquid formulation (Cat. Nos., 37581 and 37535).

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How do I select the right blocking buffer for my Western blotting application?

Please review the table in this link (https://www.thermofisher.com/us/en/home/life-science/protein-biology/protein-assays-analysis/western-blotting/detect-proteins-western-blot/western-blot-buffers.html) to pick the right Western blot blocking buffer for your specific need. Additionally, here are some general tips to keep in mind:

  • Milk-based blocking buffers are not compatible with biotin systems.
  • SuperBlock Blocking Buffers can cross-react with some antibodies raised against rabbits.
  • Blockers in phosphate-based buffers are generally not recommended in systems using alkaline phosphatase conjugates.
  • StartingBlock Buffers (Cat. Nos. 37538 and 37542) are recommended when the optimal blocking buffer has not been determined.


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Is it necessary to add Tween-20 to SuperBlock Blocking Buffers?

To prevent non-specific binding, we recommend adding 0.05% to 0.1% Tween-20 to SuperBlock Blocking Buffers that don't already contain it. Please note that Cat. Nos. 37516 and 37536 already contain 0.05% Tween 20. .

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Which applications are SuperBlock Blocking Buffers with?

SuperBlock Blocking Buffers (Cat. Nos. 37515, 37518, 37580, 37516, 37535, 37581, 37536, and 37545) are compatible with ELISA, immunohistochemistry, and Western blotting applications. SuperBlock Blocking Buffers (Cat. Nos. 37517 and 37537) are compatible only with Western blotting and immunohistochemistry applications but not with chemiluminescence.

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Can SuperBlock Blocking Buffers be used to block a flash plate?

Yes, SuperBlock Blocking Buffers can be used to block a flash plate.

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Is the proprietary protein contained in SuperBlock Blocking Buffers glycosylated?

Yes. The proprietary protein contained in SuperBlock Blocking Buffers is glycosylated. In addition, the buffers contain a proprietary simple sugar carrier/diluent.

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What is the general composition of SuperBlock Blocking buffers?

SuperBlock Blocking Buffers contain PBS or TBS, along with Kathon Anti-microbial Agent as preservative (600 ppm), with or without 0.05% Tween-20. We offer two different types of SuperBlock Blocking Buffers: one designed only for Western blotting and immunohistochemistry applications but not chemiluminescence (Cat. Nos. 37517 and 37537) and the other for general blocking with ELISA, immunohistochemistry, and Western blotting applications (Cat. Nos. 37515, 37518, 37580, 37516, 37535, 37581, 37536, and 37545).
Note: The SuperBlock (TBS) Blocking Buffer Dry Blend (Cat. No. 37545) does not contain the Kathon preservative.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

What are SuperBlock Blocking Buffers?

SuperBlock Blocking Buffers contain a proprietary protein-based formulation of blocking agents for blocking excess binding sites in ELISA, immunohistochemistry, and Western blotting applications. SuperBlock Blocking Buffers have the advantage of being free of immunoglobulins, albumin, or endogenous biotin, making them compatible in many situations where traditional blocking agents fail.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.