- Form
- Tablets and solution; DPBS solution
- Typical pH
- About 7.4
- Ask
- 1× or 10×, with or without calcium and magnesium
PBS is salt and ionic strength, not a Good's buffer. DPBS with calcium and magnesium keeps adherent cells happier. DPBS without them is the rinse before trypsin. For PBST, add Tween 20, inquired as a separate raw material.
What it is
PBS is an isotonic saline buffered by sodium and potassium phosphates. A common 1× formula is 137 mM NaCl, 2.7 mM KCl, 10 mM Na2HPO4 and 1.8 mM KH2PO4 at about pH 7.4. DPBS (Dulbecco's) has a similar composition and is sold with or without calcium and magnesium.
Where it is used
- Rinsing cells before passaging: calcium- and magnesium-free DPBS removes divalent ions ahead of trypsin.
- ELISA and Western washes as PBST, with about 0.05–0.1% Tween 20.
- Diluent for antibodies, blocking proteins and coating antigens, and for immunofluorescence staining.
- Transport and holding of tissues and cells for short periods.
Handling tips
- Phosphate precipitates with calcium and zinc. Add Ca/Mg last and slowly, or buy DPBS already formulated with them.
- 10× concentrates can crystallize in the cold; warm to room temperature and mix before diluting.
- Phosphate inhibits alkaline phosphatase, so AP-based detection often uses TBS instead.
What to specify when ordering
- PBS or DPBS, and with or without calcium and magnesium.
- Tablets, powder or liquid; 1× or 10×.
- Sterile, cell-culture tested or general lab grade, and pack size.
Properties and storage
- Formula
- —
- Molecular weight
- —
- Appearance
- Tablets / clear colourless solution
- Solubility
- Dissolve tablets in purified water per label
- Storage
- Tablets dry at room temperature; opened solution 2–8 °C
- Typical packs
- Tablets per bottle; solution 500 mL, 1 L; 10× on request
Typical literature values. The batch COA / SDS governs.
Before you inquire
Is PBS a Good's buffer?
No. It is an inorganic phosphate buffer (phosphate pKa2 about 7.2), not a zwitterionic organic buffer like HEPES.
How is PBST made?
PBS with about 0.05–0.1% Tween 20; follow your protocol.
When should I choose DPBS with calcium and magnesium?
For washing or holding cells that should stay attached and intact. Use the calcium- and magnesium-free version before trypsin or EDTA detachment.
Pack sizes and catalogue numbers
PBS tablet
CTH10010-100Bt
Prices on request; lead time confirmed on the quotation.
Phosphate Buffered Saline
CTH10011-500ml
Prices on request; lead time confirmed on the quotation.
Dulbecco's Phosphate-Buffered Saline
CTH10012-500ml
Prices on request; lead time confirmed on the quotation.
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Send an inquiryFor research or industrial use only. Not for human or animal diagnosis or treatment, and not for drug or food use. Grade, pack size and lead time follow the supplier batch COA / SDS. Figures on this site are general industry references, not a factory specification.