Sodium Citrate / Citric acid Buffer protocol
Summary of use for
Sodium Citrate/ Citric acid buffer is a common buffer in Immunohistochemistry and immunofluorescent staining applications. It is base buffer in some Pathology and cyto-pathology fixatives and easily can be mixed with formaldehyde, alcohols, and metal cell fixatives. in hematology tri-sodium citrate is choice anticoagulant for ESR test and in Blood banking it is used as anticoagulant and buffer in collected blood bags. Sodium Citrate/ Citric acid buffer is an excellent buffer for RNA and DNA Isolation and drying because it prevents them from auto-degradation and oxidation. There is specific usage for Sodium Citrate/ Citric acid buffer in Microbiology and Bacteria diagnosis, in fact citrate test is one of important tests in routine microbiology for detecting Enterobacteriaceae. Sodium Citrate/ Citric acid buffer is affordable, Stable to sunlight and temperature change and precipitation.
In ELISA, Sodium Citrate/ Citric acid buffer is a choice buffer for conjugation of HRP with Abs / Proteins by Sodium Periodate method. Also, it is a good choice for protein elution in Immunochromatography and protein dialysis. Sodium Citrate/ Citric acid buffer is an effective buffer system for protein drying and crystallization protocols and preserve proteins from oxidation and misfolding. Sodium Citrate/ Citric acid buffer is normally the proper choice for mildly acidic PH from 3.2 – 6.0. In ELISA application some protocols have been developed for ELISA TMB Substrate by Sodium Citrate/ Citric acid buffer, PH:3.4, But the most important application for Sodium Citrate/ Citric acid buffer is HRP-Conjugation with sodium periodate method.
Sodium Citrate / Citric acid Buffer protocol
Sodium Citrate / Citric acid buffer preparation (0.1 M) PH:5
- Prepare 950 mL of distilled water in a suitable container.
- Add 17.099 g of Sodium Citrate dihydrate to the solution.
- Add 8.042 g of Citric Acid to the solution.
- Adjust solution to final desired pH using HCl or NaOH
- Add distilled water until the volume is 1 L.
Note1: Do not adjust PH with Citric acid, because it can change buffer molarity.
Note2:Sodium acetate buffer PH 4.5 – 5 is usually a standard buffer for immunochromatography, Immunohistochemistry, protein dialyzing and Ab conjugation.