HEPES VS PBS (phosphate buffered saline)

Biological buffers can stabilize the pH value of aqueous solutions, so they are widely used in biological experiments. And the traditional buffers used in the past , Such as carbonate buffer and phosphate buffer, are usually not suitable for many biological experiments. These reagents cannot effectively buffer above pH 7.5. And there will be some interference reactions. Therefore, in 1966, Dr. Norman Good and others proposed a series of solutions that can solve the limitations of traditional buffers. Prepared zwitterionic buffers, these buffers have a pKa value equal to or close to the physiological pH value, are non-toxic to cells, and will not pass through cell membranes absorb. The following are the advantages and disadvantages of the more commonly used PBS (phosphate buffered saline) and HEPES.
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HEPES
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PBS
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Valid pH range
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6.8-8.2
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5.8-8.0
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Biological toxicity
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Not biologically toxic
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Not biologically toxic
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Osmotic pressure
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Using 0.1 M HEPES significantly increased the osmotic pressure of the medium.
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With the characteristic of iso-osmotic pressure, it can prevent cell rupture.
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Cell Viability
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Higher maximum cell density and viability can be seen in the HEPES buffer system.
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Cell culture samples diluted in PBS may inadvertently reduce cell viability.
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Relationship with metal ions
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Negligible metal ions generate complexes or precipitates.
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Combined with some metal ions will produce complexes or precipitates.
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Relationship with enzymatic reaction
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Suitable for enzymatic reactions
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May inhibit enzymatic reactions
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Changes under freezing conditions
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Freezing of HEPES solution will not cause pH changes.
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The freezing of the PBS solution causes a significant pH change.
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Autoclave sterilization
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Not autoclavable
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Can be autoclaved
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Prefix fixative for electron microscope research
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Hepes instead of PBS avoids this kind of precipitation
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Because phosphate is related to divalent cations. A higher concentration of PBS will cause serious precipitation, which prevents cells from effectively filtering onto the filter.
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For chromatography
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Applicable in chromatography
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Applicable in chromatography
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HClO fluorescence detection
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Not applicable
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Applicable
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