Control Standard Endotoxin (CSE) — Bacterial Endotoxin Reference Standard for LAL/TAL Assays

Every endotoxin test needs a positive control. Without one, a negative result is just an untested result.

The FireGene Control Standard Endotoxin (CSE) is a freeze-dried bacterial endotoxin preparation extracted from Escherichia coli serotype O111:B4, the reference strain used in pharmacopeial endotoxin standard preparations worldwide. Potency is calibrated against the national standard bacterial endotoxin and expressed in Endotoxin Units (EU), where 1 EU = 1 IU (international unit) of endotoxin activity.

Bacterial endotoxin standards are extracted from Escherichia coli (E. coli O111:B4), freeze-dried with lactose and polyethylene glycol as excipients, and their titer is calibrated based on the national standard bacterial endotoxin.

Application:

• Perform Limulus Reagent Sensitivity Recheck Test
• Perform interference tests,
• Serve as various positive controls.

This product can be used in both the Gel Clot Endotoxin Test Assay series experiments and the Kinetic Chromogenic Endotoxin Test series experiments.

The Control Standard Endotoxin (CSE) serves as various positive controls.

SPECIFICATIONS
Package	10 Pcs/kit
Potency	10-100 EUR/Pcs. Bacterial endotoxin content is expressed in endotoxin units (EU) One EU is equivalent to 1 international unit of endotoxin content (IU).
Application	Test for Confirmation of Labeled Lysate Sensitivity, Test for Interfering Factors, positive controls.
Storage	At 2-8°C the product can be stored for 24 months before opening.
Traits	White or almost white freeze-dried powder, easily soluble in water.

 

Product FAQ

Q: What concentration of CSE should I use for lysate sensitivity recheck?

A: For gel-clot sensitivity recheck, prepare a geometric dilution series of CSE at 2λ, λ, 0.5λ, and 0.25λ (where λ is the labeled sensitivity of your LAL/TAL reagent). All four concentrations must be tested in duplicate. The geometric mean of the endpoint titers must fall within 0.5λ to 2λ for the sensitivity to be confirmed per USP <85>.

Q: How do I reconstitute the CSE vial?

A: Add the volume of LAL reagent water (endotoxin-free water) specified in the vial label or user manual. Vortex vigorously for at least 15 minutes before use — incomplete reconstitution is one of the most common sources of false results in BET workflows. Use FireGene Endotoxin Assay Water and Pyrogen-Free Vials to avoid introducing exogenous endotoxin during dilution.

Q: Can I use one CSE lot for both gel-clot and kinetic chromogenic testing?

A: Yes. The same CSE lot is compatible with Gel-Clot, Kinetic Chromogenic, and End-Point Chromogenic LAL/TAL assay formats. Potency in EU/vial applies equally across all three methods.

Q: How many tests can I run from one kit?

A: Each kit contains 10 vials at 15 EU/vial. The number of tests per vial depends on your sensitivity level and dilution scheme. For typical gel-clot sensitivity recheck at 0.06 EU/mL, one vial supports multiple dilution series. Contact service@firegene.com if you need guidance on calculating how many vials your protocol requires per run.

Q: Is a custom potency (EU/vial) available?

A: Yes. Potency options outside the standard 15 EU/vial configuration are available on request. Email service@firegene.com with your required concentration and intended application.