TBST Buffer 20× pH8.0: Uses, Preparation & FAQs
TBST Buffer 20× pH8.0: Uses, Preparation & FAQs
TBST Buffer (20×, pH8.0) is a concentrated, ready-to-dilute Tris-buffered saline solution containing Tween-20 detergent, widely used as a membrane washing buffer in Western blotting, ELISA, and other immunodetection workflows.
- Product SKU
- T1529794
- Concentration
- 20× (concentrated stock)
- pH
- 8.0
- Working Dilution
- Dilute 1:20 with ultrapure water to prepare 1× TBST
- Key Components
- Tris base, NaCl, Tween-20 (polysorbate 20)
- Primary Application
- Membrane washing in Western blot; blocking and antibody incubation rinse steps
What Is TBST Buffer and What Are Its Components?
TBST (Tris-Buffered Saline with Tween-20) is one of the most commonly used wash buffers in molecular biology and immunodetection protocols. It is composed of three key components: Tris base (providing buffering capacity), sodium chloride (NaCl, maintaining ionic strength and physiological salt conditions), and Tween-20 (a non-ionic detergent that reduces non-specific hydrophobic interactions between antibodies and the membrane).
Aladdin Scientific's TBST Buffer (20×, pH8.0) (SKU: T1529794) is supplied as a 20-fold concentrated stock solution at pH 8.0, which is the standard pH for most Western blot applications. The 20× format minimizes storage space and extends shelf life while offering convenience for high-throughput laboratories.
How to Dilute and Prepare 1× TBST Working Solution
To prepare 1× working TBST from the 20× stock, add 1 part of TBST Buffer (20×, pH8.0) to 19 parts of ultrapure (deionized) water and mix thoroughly. For example, to prepare 1 liter of 1× TBST, combine 50 mL of the 20× stock with 950 mL of ultrapure water.
It is strongly recommended to use ultrapure or Type 1 water to avoid introducing contaminants such as heavy metals, endotoxins, or microbial matter that could compromise immunodetection results. Once prepared, the 1× working solution should ideally be used within 1–2 weeks when stored at 4 °C, or within the day if kept at room temperature, to prevent microbial growth and Tween-20 degradation.
Quick Reference:
- To make 100 mL 1× TBST: 5 mL of 20× stock + 95 mL ultrapure water
- To make 500 mL 1× TBST: 25 mL of 20× stock + 475 mL ultrapure water
- To make 1 L 1× TBST: 50 mL of 20× stock + 950 mL ultrapure water
Applications of TBST Buffer in Research Protocols
Western Blotting (Immunoblotting): TBST is the standard wash buffer used between blocking, primary antibody incubation, and secondary antibody incubation steps. Typically, membranes (PVDF or nitrocellulose) are washed 3–5 times for 5–10 minutes each with 1× TBST to remove unbound antibodies and reduce background signal.
ELISA: TBST or PBST (PBS with Tween-20) are used as wash buffers between incubation steps to remove non-specifically bound proteins and reduce assay background.
Immunoprecipitation (IP) and Co-IP: TBST may be used as a wash buffer for protein–antibody–bead complexes to maintain specificity while preserving protein interactions.
Dot Blot and Slot Blot: TBST is applied as a rinse solution after antibody incubations, analogous to Western blotting workflows.
The pH 8.0 formulation is particularly suited to applications using alkaline phosphatase (AP)-conjugated secondary antibodies, and is also compatible with HRP-conjugated detection systems.
Storage, Stability, and Handling Recommendations
Storage of 20× Stock: Store the concentrated TBST Buffer (20×, pH8.0) at room temperature (15–25 °C) or at 4 °C, protected from direct sunlight. Consult the product label or certificate of analysis for the specific expiry date.
Prepared 1× Working Solution: Store at 4 °C for up to 1–2 weeks. Discard if turbidity, precipitation, or signs of microbial contamination are observed.
Handling Precautions: Tween-20 is a surfactant; avoid generating excessive foam during mixing. Gentle inversion or stirring is preferred over vigorous vortexing. Always use clean, RNase/DNase-free containers if downstream nucleic acid work is planned alongside immunodetection assays.
pH Verification: If precise pH is critical for your assay, verify the pH of the 1× working solution after dilution, as dilution of buffered concentrates can occasionally shift pH slightly depending on water quality.
Frequently asked questions
What is the difference between TBST and PBST, and when should I use each?
TBST uses Tris-HCl as the buffering agent (typically pH 7.4–8.0), while PBST uses phosphate-buffered saline (PBS, typically pH 7.2–7.4). TBST at pH 8.0 is generally preferred for Western blotting because it is compatible with both HRP and AP detection systems and provides a slightly alkaline environment that minimizes non-specific binding. PBST is more commonly used in ELISA workflows. The choice may also depend on the antibody supplier's recommendations.
Can I reuse 1× TBST working solution across multiple washes or experiments?
It is not recommended to reuse TBST working solution between different experiments, as repeated use can introduce protein contamination from membranes and promote microbial growth, which may increase background noise. Within a single experiment, the same batch of freshly prepared 1× TBST may be used for sequential wash steps. Always inspect for turbidity or contamination before use, and discard any solution that appears cloudy.
Why is the TBST Buffer supplied at 20× concentration rather than ready-to-use 1×?
The 20× concentrated format offers several practical advantages: it reduces shipping volume and cost, lowers the risk of microbial contamination during storage (high salt concentration is inhibitory to most microbes), and allows laboratories to prepare only the volume of 1× working solution needed, minimizing waste. The concentrated format also has a longer shelf life compared to ready-to-use 1× solutions.
Does the pH 8.0 formulation affect my Western blot results compared to pH 7.4 TBST?
For most standard Western blotting protocols, both pH 7.4 and pH 8.0 TBST deliver comparable washing efficiency and signal-to-noise ratios. pH 8.0 is slightly preferred when using alkaline phosphatase (AP)-conjugated secondary antibodies, as AP has optimal activity at slightly alkaline pH. For HRP-based detection, either pH is generally acceptable. If your protocol specifies a particular pH, follow those recommendations.
How should I handle precipitation observed in the 20× TBST stock bottle?
Salt crystallization in concentrated buffer stocks is a common and reversible phenomenon, especially after cold storage or shipping. To redissolve precipitates, warm the bottle to room temperature (or gently warm in a 37 °C water bath) and mix by gentle inversion until the solution is clear. Do not autoclave or heat above 50 °C, as this may affect Tween-20 integrity. Once fully dissolved, the buffer is ready to use.
References
- Mahmood T, Yang PC. Western blot: technique, theory, and trouble shooting. N Am J Med Sci. 2012;4(9):429-434. PMID:23050259
- Kurien BT, Scofield RH. Western blotting: an introduction. Methods Mol Biol. 2015;1312:17-30. PMID:26043986
- Aladdin Scientific. Product Information: TBST Buffer (20×, pH8.0), SKU T1529794. Aladdin Scientific.
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.
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