Written and maintained by CASRAI Editorial Board
Last updated
For research use only. This page gives general product and bench-handling information from the manufacturer’s user guide and the original paper; it is not medical advice and not a protocol for any clinical use.
Short answer
B-27 Supplement (also written B27) is a serum-free supplement sold as a 50X liquid for culturing central nervous system neurons. It is normally added at 2% to Neurobasal Medium or Neurobasal-A Medium so that neuron cultures stay nearly free of glia without an astrocyte feeder layer. This page is about the cell culture reagent; “B-27” is also the name of an unrelated paper silhouette target and a bomber, which this page does not cover.
What B-27 Supplement is (and what B-27 is not)
Gibco’s user guide (Pub. No. MAN0007313) describes B-27 Supplement as “an optimized serum-free supplement used to support the growth and viability of embryonic, post-natal, adult, hippocampal and other central nervous system (CNS) neurons.” It is supplied as a 50X liquid and includes a cocktail of antioxidants to reduce reactive oxygen damage. The guide does not publish a full ingredient table in its text, so for exact contents use the manufacturer’s safety data sheet or technical documentation rather than a third-party list.
Searches for “B-27” also return shooting-target and aircraft pages. Those are unrelated uses of the label and have nothing to do with the supplement.
What does B27 stand for? Where the name comes from
None of the sources read for this page expands “B27” into words. It is the name of the formulation reported by Brewer, Torricelli, Evege and Price in 1993 (J Neurosci Res 35(5):567-576, PubMed 8377226), “Optimized survival of hippocampal neurons in B27-supplemented Neurobasal, a new serum-free medium combination.” The authors optimized the concentrations of 20 components of an earlier serum-free formulation for embryonic rat hippocampal neurons. They reported more than 60% survival at 4 days at densities above 160 cells/mm2 with glia below 0.5%. The paired Neurobasal medium was designed with lower osmolarity than DMEM, reduced cysteine and glutamine, and ferrous sulphate removed from the DME/F12 base.
How B-27 is used with Neurobasal medium
What is Neurobasal medium supplemented with B27 used to grow?
Per the Gibco guide, the combination is used to grow nearly pure populations (under 0.5% glial cells) of neuronal cells without an astrocyte feeder layer. The guide lists these uses:
- Neurobasal Medium plus B-27 for pre-natal (embryonic) neurons.
- Neurobasal-A Medium plus B-27 for post-natal and adult brain neurons.
- Neurobasal plus B-27 for neuronal-origin tumor cell lines.
- DMEM/F-12 with GlutaMAX plus B-27 for expansion of EGF-responsive precursor cells from rat embryonic striatum and mesencephalon.
The guide states the supplement was tested on freshly isolated E18 rat hippocampal and cortical neurons, Gibco primary rat cortex and hippocampus neurons, and neuroblastoma lines. Surfaces for primary neurons are typically coated first; see Poly-D-Lysine: Cell Culture Coating Guide. For a very different cell type and its media, compare HEK 293 cells and their media.
B27 vs B27 Plus supplements
What is the difference between B27 and B27 Plus?
B-27 Plus is a later product line from the same manufacturer. The table reflects the user guide for the classic supplement and manufacturer listings for the Plus system; check the current label for the lot you hold.
| Item | B-27 Supplement (50X) | B-27 Plus (listing level) |
|---|---|---|
| Form | 50X liquid supplement | Serum-free supplement; sold as a system with Neurobasal Plus medium |
| Paired medium | Neurobasal or Neurobasal-A (DMEM/F-12 for precursor expansion) | Neurobasal Plus |
| Cell types named | Embryonic, post-natal, adult and hippocampal CNS neurons | Primary rodent and human stem-cell-derived neurons |
| Storage | -20 C to -5 C, protected from light; 12 months from date of manufacture | -5 C to -20 C, protected from light; do not freeze-thaw more than twice |
A “minus vitamin A” (vitamin A-free) variant of the supplement is also listed by the manufacturer; its intended purpose is not stated in the sources read here, so check its product documentation before substituting it.
Handling and storage checklist (from the user guide)
- Store the 50X supplement at -20 C to -5 C, protected from light. Shelf life is 12 months from date of manufacture.
- Thaw overnight at 4 C before use.
- Add the supplement aseptically to Neurobasal Medium at 2% (20 mL per litre), and add GlutaMAX to 0.5 mM (2.5 mL per litre).
- Remaining supplement may be aliquoted and stored at -20 C to -5 C. Do not freeze-thaw more than twice.
- Do not leave thawed supplement at 4 C for more than two weeks.
- Complete medium is stable up to one week at 2-8 C in the dark.
- Primary rat hippocampal cultures need an additional 25 uM L-glutamate up to day 4 of culture, per the guide.
Aliquoting limits and temperature windows are a cold-chain question as much as a culture one; see Cold Chain Management for Medical Supplies and the lab equipment and supplies procurement guide for how labs track them.
Common misunderstandings
- It is not a complete medium. It is a supplement added to a basal medium such as Neurobasal.
- It is not only for hippocampal neurons. The guide names embryonic, post-natal, adult and other CNS neurons, plus certain tumor lines and precursor cells.
- It is not for diagnostic use. The guide labels it “For Research Use Only. Not for use in diagnostic procedures.”
- The shooting target is unrelated. A search for “AB 27 target” or “B-27 target” concerns a different product entirely.
FAQ
What does B27 stand for?
The name comes from the 1993 Brewer et al. paper; the sources read do not expand it into words.
What is AB 27 target?
It is not related to the cell culture supplement; it refers to a target product. This page does not cover it.
What is the difference between B27 and B27 Plus supplements?
See the table above: B-27 Plus is sold with Neurobasal Plus medium and is listed for primary rodent and human stem-cell-derived neurons.
What is Neurobasal medium supplemented with B27 used to grow?
Nearly pure CNS neuron cultures without an astrocyte feeder layer, plus the other uses listed above.
Sources
- Thermo Fisher Scientific (Gibco), B-27 Supplement (50X) User Guide, Pub. No. MAN0007313 Rev 3.0, read 2026-11-07: documents.thermofisher.com.
- Brewer GJ, Torricelli JR, Evege EK, Price PJ. J Neurosci Res 1993;35(5):567-576, read 2026-11-07: PubMed 8377226.
- Fisher Scientific product listing for the B-27 Plus Neuronal Culture System, read 2026-11-07 (listing-level information): fishersci.com.
