5 bromo 4 chloro 3 indolyl β d galactopyranoside x gal  (Amresco)

Journal: Food Chemistry: Molecular Sciences

Article Title: Usage of nanobody-beta-galactosidase fusion in immunoassays and its application in detecting a peanut allergen

doi: 10.1016/j.fochms.2026.100357

Figure Lengend Snippet: Tagging a nanobody to the N-terminus of β-gal does not affect its activity. (A) Colonies of dH5α bacteria transformed with a plasmid containing the coding sequence for β-gal with Nb16 fused to its N-terminus via a 4AA (GSHV) linker and plated on an LB/Kan plate with IPTG and X-gal. The plate was photographed 24 h after incubation at 37 °C for 16 h. (B), (C), and (D) are the same as (A), except that the bacteria were induced to express β-gal with Nb16 fused to its N-terminus via a longer flexible peptide (GSGASGSHV), a Strep-tag-containing peptide (GSWSHPQFEKHV), or β-gal with purification tags, respectively.

Article Snippet: Milli-Q water was purified in-house using a Milli-Q Advantage A10 system (Millipore, Bedford, MA, USA) and used throughout. o -Nitrophenyl-β-galactoside (ONPG), Isopropyl β-D-1-thiogalactopyranoside (IPTG), Kanamycin (Kan), and X-Gal were purchased from GoldBio (St Louis, MO, USA).

Techniques: Activity Assay, Bacteria, Transformation Assay, Plasmid Preparation, Sequencing, Incubation, Strep-tag, Purification

Journal: bioRxiv

Article Title: Selective Hydrolytic Defluorination of Branched Perfluorooctanoic Acid Isomers by a Haloacid Dehalogenase

doi: 10.64898/2026.04.19.719434

Figure Lengend Snippet: (a) Docking model showing PFOA bound within the active-site pocket of 4A. (b) Enlarged view of the PFOA-binding site, illustrating predicted hydrogen-bonding interactions between the PFOA carboxylate group and surrounding active-site residues. (c) Two-dimensional interaction map of the PFOA–4A complex, highlighting hydrogen-bonding interactions involving the carboxylate group (green dashed lines) and hydrophobic or polar contacts between PFOA and active-site residues. (d) Biosensor-based plate assay detecting fluoride release following high-concentration, scaled-up reactions. PFOA (0.5 mM) was incubated with purified 4A (500 µM) at 20℃ for 120 h prior to analysis. Following incubation, aliquots from the reaction mixture were analyzed using a fluoride-responsive riboswitch biosensor with 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-gal) as the chromogenic substrate. Enzyme-only, substrate-only, buffer-only controls, and fluoride standards (10 and 500 μM KF) are shown.

Article Snippet: 5-Bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-gal) solution (20 mg/mL; Thermo Fisher Scientific, RO941) and 10 mM Tris buffer (pH 8.0, prepared from a 1 M stock; Thermo Fisher Scientific, AM9855G) were used for enzyme assays.

Techniques: Binding Assay, Concentration Assay, Incubation, Purification