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10X Citrate Buffer *pH 6.0*
Ordering information
| Price | |
| Catalog Number | |
| Unit Size | |
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Additional ordering information
| Telephone | 1-800-990-8053 |
| Fax | 1-800-609-2943 |
| sales@aatbio.com | |
| International | See distributors |
| Bulk request | Inquire |
| Custom size | Inquire |
| Shipping | Standard overnight for United States, inquire for international |
Physical properties
| Solvent | Water |
Storage, safety and handling
| H-phrase | H303, H313, H333 |
| Hazard symbol | XN |
| Intended use | Research Use Only (RUO) |
| R-phrase | R20, R21, R22 |
| Storage | Refrigerated (2-8 °C) |
| Overview |  SDSProtocol |
See also: Buffers and Lab Consumables
A citrate buffer is an aqueous solution composed of a weak acid (citric acid) and its conjugate base (sodium citrate). It is sometimes called a citric acid buffer, sodium citrate buffer, or citric acid-sodium citrate buffer. Citric acid is a polyprotic acid with three pKa's at 3.13, 4.76, and 6.40. It has a buffering range between pH 3.0 to 6.2. (Dawson 2002, Nozawa 1995).
Heat-Induced Epitope (Antigen) Retrieval (HIER) techniques are a common application that uses a citrate buffer. These techniques help regain lost antigenicity that may occur in formalin-fixed paraffin-embedded (FFPE) tissue. During fixation, formalin and other aldehyde compounds are hypothesized to create protein crosslinks with antigenic sites in tissue specimens, resulting in conformational changes that mask these epitopes leading to poor downstream detection during fluorescence in situ hybridization (FISH) or immunohistochemistry (IHC). Applying HIER, which uses heat treatment in citrate buffer (0.01 - 0.1 M), aldehyde crosslinks formed during fixation are theorized to be reduced, restoring lost antigenicity and improving downstream detection and signal quality. (Krenacs 2010).
Heat-Induced Epitope (Antigen) Retrieval (HIER) techniques are a common application that uses a citrate buffer. These techniques help regain lost antigenicity that may occur in formalin-fixed paraffin-embedded (FFPE) tissue. During fixation, formalin and other aldehyde compounds are hypothesized to create protein crosslinks with antigenic sites in tissue specimens, resulting in conformational changes that mask these epitopes leading to poor downstream detection during fluorescence in situ hybridization (FISH) or immunohistochemistry (IHC). Applying HIER, which uses heat treatment in citrate buffer (0.01 - 0.1 M), aldehyde crosslinks formed during fixation are theorized to be reduced, restoring lost antigenicity and improving downstream detection and signal quality. (Krenacs 2010).
- Dawson, Rex Malcolm Chaplin, et al. Data for biochemical research. Vol. 3. Clarendon press, 2002.
- Krenacs, Laszlo, et al. "Heat-induced antigen retrieval for immunohistochemical reactions in routinely processed paraffin sections." Immunocytochemical Methods and Protocols. Humana Press, 2010. 103-119.
- Nozawa, S. R., et al. "Mind the buffering capacity of citric acid." Fungal Genetics Newsletter 42 (1995): 56.
Example protocol
AT A GLANCE
Storage
2-8°C. DO NOT FREEZE
Intended Use:
1X buffer solution is intended for heat-induced antigen retrieval in IHC. Please refer to the primary antibody protocol.
Reagent
10X, pH 6 Citrate Buffer.
PREPARATION OF WORKING SOLUTION
Dilute 10X buffer as needed (e.g., 10 mL of 10X Citrate buffer + 90 mL of distilled water), and mix well.
Note: 1X citrate buffer can be stored at 2-8°C.
Images
Figure 1. Titration curves of 5 mM citric acid (50 ml) with 100 mM NaOH (●) and 20 mM MES (50 ml) with 100 mM NaOH (○) (Nozawa 1995).