Chromogenic lal assay

Manufactured by Lonza

The Chromogenic LAL assay is a laboratory test used to detect and quantify the presence of bacterial endotoxins, also known as lipopolysaccharides (LPS), in various samples. It provides a reliable and sensitive method for assessing the purity and safety of pharmaceutical, medical, and other products that may be susceptible to endotoxin contamination.

Automatically generated - may contain errors

Lab products found in correlation

Freestyle medium, by Thermo Fisher Scientific (1 mentions) Kta fplc system, by GE Healthcare (1 mentions) Rprotein a sepharose fast flow resin, by GE Healthcare (1 mentions) Talon resin, by Takara Bio (1 mentions) Optipro serum free medium, by Thermo Fisher Scientific (1 mentions) Pcep4, by Thermo Fisher Scientific (1 mentions) Talon metal affinity resin, by Takara Bio (1 mentions) Expi293 expression system, by Thermo Fisher Scientific (1 mentions) Q5 site directed mutagenesis kit, by New England Biolabs (1 mentions)

3 protocols using chromogenic lal assay

Production and Purification of Murine PD-1 Protein

Check if the same lab product or an alternative is used in the 5 most similar protocols

Proteins were produced in-house using suspension HEK293-F (Life Technologies, R79007), which were cultured in Freestyle medium (Life Technologies). HEK293 cells were transfected with sterile-filtered plasmid DNA using polyethylenimine in OptiPro serum-free medium (Thermo Fisher). The murine PD-1 ectodomain monoFc protein fusion and monovalent antibodies were HIS-tagged and purified by gravity column using TALON resin (Takara Bio Inc.). All bivalent antibodies were purified by gravity column using rProtein A Sepharose Fast Flow resin (GE Healthcare). All proteins were characterized by Coomassie-stained SDS NuPAGE Bis-Tris protein gels (Thermo Fisher Scientific). Proteins were further purified by size exclusion chromatography, if aggregation was detected on the protein gel, using a HiLoad 16/600 Superdex 200 pg column (Millipore Sigma) on an ÄKTA FPLC system (GE Healthcare). After purification, all proteins were buffer exchanged into sterile phosphate-buffered saline (PBS) (Corning), 0.2 μm sterile-filtered (Pall Corporation), and confirmed to contain minimal endotoxin (<0.1 EU per injection) using a chromogenic LAL assay (Lonza). All proteins were flash-frozen by liquid nitrogen, stored at −80°C and thawed on ice before use.

Cowles S.C., Sheen A., Santollani L., Lutz E.A., Lax B.M., Palmeri J.R., Freeman G.J, & Wittrup K.D. (2022). An affinity threshold for maximum efficacy in anti-PD-1 immunotherapy. mAbs, 14(1), 2088454.

+ Open protocol

+ Expand

Cholesterol Crystals Preparation and Endotoxin Evaluation

Cited 1 time

Check if the same lab product or an alternative is used in the 5 most similar protocols

CC were prepared as described by Samstad et al.(10 (link)). Briefly, ultrapure cholesterol (100 mg) was dissolved in 1-propanol (50 mL and aggregated by the addition of distilled water. CC were air dried and suspended in 0.05% (w/v) HSA/PBS. After preparation, the endotoxin contamination was measured in a Chromogenic LAL Assay (Lonza). The Lipopolysaccharide (LPS) was below the detection limit (0.1 EU/mL) in sample size of 50 mg/mL CC, and thus the endotoxin content would be below 0.18 pg/mg CC.

Gravastrand C.S., Steinkjer B., Halvorsen B., Landsem A., Skjelland M., Jacobsen E.A., Woodruff T.M., Lambris J.D., Mollnes T.E., Brekke O.L., Espevik T, & Rokstad A.M. (2019). Cholesterol Crystals Induce Coagulation Activation through Complement-Dependent Expression of Monocytic Tissue Factor. The Journal of Immunology Author Choice, 203(4), 853-863.

+ Open protocol

+ Expand

Generation and Purification of IL-2-Fc Fusion Proteins

Check if the same lab product or an alternative is used in the 5 most similar protocols

For the generation of IL-2-Fc-fusion proteins, regions encoding human IL-2 (residues Ala1–Thr133) were genetically fused to murine Fc (IgG2c Glu216–Lys447, Eu antibody numbering48 (link)) containing a mutated C1q-binding site (E318A, K320A and K322A)49 by means of a short glycine-serine linker (GSGS). The construct was generated by gene synthesis (GeneArt) and cloned into the mammalian expression vector pCEP4 (Thermo Fisher). Disruption of the CD25 and FcγR binding sites and restoration of the C1q binding site were performed using the Q5 site-directed mutagenesis kit (NEB) using custom-designed primers, followed by validation of mutations by Sanger sequencing. IL-2-Fc constructs were used to transfect suspension-adapted HEK293 cells using the Expi293 expression system (Thermo Fisher). Protein purification was performed with protein G agarose beads (ACROBiosystems) using disposable columns (Thermo Fisher). All protein preparations were quality controlled for endotoxin levels, as measured by chromogenic LAL assay (Lonza). Genetic constructs coding for the ectodomains of hCD25 and hCD122 (in pCEP4, C-terminal His-tagged) were purchased from Genscript, expressed as above and purified using the TALON metal affinity resin (Clontech).

Vazquez-Lombardi R., Loetsch C., Zinkl D., Jackson J., Schofield P., Deenick E.K., King C., Phan T.G., Webster K.E., Sprent J, & Christ D. (2017). Potent antitumour activity of interleukin-2-Fc fusion proteins requires Fc-mediated depletion of regulatory T-cells. Nature Communications, 8, 15373.

+ Open protocol

+ Expand

About PubCompare

Our mission is to provide scientists with the largest repository of trustworthy protocols and intelligent analytical tools, thereby offering them extensive information to design robust protocols aimed at minimizing the risk of failures.

We believe that the most crucial aspect is to grant scientists access to a wide range of reliable sources and new useful tools that surpass human capabilities.

However, we trust in allowing scientists to determine how to construct their own protocols based on this information, as they are the experts in their field.

Ready to get started?

Revolutionizing how scientists
search and build protocols!