Artificial Cerebrospinal Fluid (ACSF)

Catalog No.: DCP-ACSF

Size:  500 mL
Storage:  4°C, protected from light
Shipping Condition:  Blue Ice

Sterile:  Filtered 0.1-micron membarne TWICE, 0.04-micron membrane ONCE
Shelf Life:  4 months at 4°C, Dark-light protected case, and Oxygen-control container
                   4 weeks after opening product, Soter at 4°C in dark, aluminum-foiled condition 

RESEARCH USE ONLY;  Not for clinical use

Advanced and improved relative to traditional ACSF:

• Dual buffer (HEPES + HCO₃).
• Elevated glucose and added pyruvate for energy support and ROS scavenging.
• Taurine and glutamine for osmotic and metabolic support.
• Moderate ascorbate plus chelators for neuroprotection with realistic stability.

Role of Chelators and Cold Storage:

• EDTA + DTPA trap traces of Fe³/Cu² that otherwise catalyze ascorbate autoxidation and Fenton-type reactions.
• Storage at 2–8°C slows all degradation pathways (ascorbate oxidation, glutamine degradation), as used in parenteral vitamin C and antibiotic solutions.
• Combined with oxygen-barrier packaging and inert gas headspace, this strategy is consistent with 6–12 month stability for similar aqueous formulations.

• Keeps the full ion profile of standard ACSF (no NMDG in final perfusate, so fully physiological).
• Adds dual buffering (HEPES + bicarbonate), elevated glucose, pyruvate, taurine, glutamine, and moderate ascorbate – all shown to improve tissue viability and metabolic resilience in brain slice and CSF models.
• Uses chelator-stabilized antioxidant system analogous to clinical ascorbate formulations that are stable for months when bottled under nitrogen and protected from light.

pH:

• pH at 25°C (sealed, storage): ~7.1–7.2
• pH at 32–34°C after carbogen bubbling: 7.35–7.45

Compsition:
 

Components	Function & Rationale
NaCl	Main extracellular Na+, osmotic backbone of ACSF
NaHCO₃	Primary CO₂/HCO₃- buffer; requires carbogen bubbling to reach final pH
KCl	Maintains physiological K+ gradient across membrane
NaH₂PO₄·H₂O	Secondary phosphate buffer; stabilizes pH during storage
MgCl₂·6H₂O	Divalent cation; limits NMDA excitotoxicity, neuroprotective
CaCl₂·2H₂O	Physiological Ca2+ for synaptic transmission; added last during manufacturing to avoid precipitation
Glucose	Elevated from 10 mM; surplus energy for long recording windows
HEPES (Na salt)	Dual buffer with bicarbonate; stabilizes pH during handling gaps and storage
Na-pyruvate	ROS scavenger; alternative TCA substrate; neuroprotective
L-Glutamine	Most abundant CSF amino acid; metabolic and neurotransmitter support
Taurine	Osmoregulator, mild antioxidant, neuromodulator in CSF
Na-ascorbate	Moderate antioxidant level chosen for stability in RTU format; chelators protect from oxidation
Disodium EDTA	Chelates Fe³+/Cu²+; prevents metal-catalyzed ascorbate oxidation
DTPA	Additional chelator; synergistic with EDTA for robust metal control
N-acetylcysteine (NAC)	Additional chelator; synergistic with EDTA for robust metal control

Quality Control:

• Appearance: Clear, colorless, no visible particles
• pH (sealed, 25°C): 7.1–7.2
• Osmolality: 300–315 mOsm/kg
• Na+, K+, Ca²+, Mg²+, Cl^-: Within ±5% of nominal
• Glucose: 24–26 mM
• Pyruvate: 2.7–3.3 mM
• Ascorbate: ≥90% of label at 6 months
• Taurine, Glutamine: 90–110% label
• Sterility: Pass USP <71>
• Endotoxin:  <0.5 EU/mL
• Particulate matter: USP <788> (≤25/mL ≥10µm, ≤3/mL ≥25µm)

End-User Protocol:

* We do not provide gas mixture 5% CO2 + 95% O2 for the gas bubbling process to maintain the pH of the ACSF.

This is the simplified field protocol for your customers. All formulation/sterilization complexity stays at the factory.

1. Remove the bottle from cold storage.

• Take ACSF from 2–8°C storage. (Optional) . Pre-warm the solution to a desired temperature for experimental procedures.

2. Carbogen bubbling (only required user “prep”)

• Connect a sterile gas line delivering 95% O₂ / 5% CO₂ to the solution via a 0.1-μm disc filter.
• Bubble for 10–15 minutes. 
• Brings pH into the 7.35–7.45 range via the bicarbonate buffer system. Fully oxygenates the solution for optimal tissue viability.

3. Connect to the perfusion system

• Attach the outlet port to the lab’s perfusion line using sterile connectors.
• Begin perfusion at the desired flow rate (typically 2–3mL/min for slice chambers).

4. Use the window and disposal

• Use within one working day after first opening (e.g., 8–12 hours of active use).
• Keep the system closed and avoid repeated disconnection to prevent contamination (no preservative is added, relying on sterility).
• Discard any remaining volume at the end of the day or if the solution becomes cloudy, discolored, or shows precipitate.

Troubleshooting Guide

Problem	Likley Cause	Solution
Poor seal formation (>30 sec)	Old animal tissue, insufficient recovery time	Use NMDG protocol, extend recovery to 15 min
High series resistance	Damaged cells, divalent cation imbalance	Check Ca²+/Mg²+ concentrations, reduce slice thickness
Rapid rundown	Oxidative stress, insufficient antioxidants	Increase ascorbate to 10 mM, check fresh preparation
Precipitation after Ca²+ addition	pH too high, added Ca²+ before pH adjustment	Adjust pH to 7.3-7.4 FIRST, then add Ca²+ slowly while stirring
Cloudy solution	Contamination, expired components	Discard, sterilize equipment, use fresh antioxidants
Low viable neuron yield	Poor slicing technique, inadequate oxygenation	Use glycerol cutting solution, check carbogen flow rate

  

* All DiagnoCine Precision Sterile prodcuts are filtered-sterilized with a 0.1-micron filtration two times and 0.04 micron once. Thus, mycoplasma contamination is prevented.  The smallest size mycoplasma type can be about 0.2 microns.

* This product is manufactured under ISO 13485-certified and CE-approved facilities (Suppliers of DiagnoCine Precision). All final packaging, quality assurance, and testing are done at the DiagnoCine R&D and Quality Testing Center.  All specific customization requests and assembly were accomplished at DiagnoCine Precision in Totowa, New Jersey, USA