β-Galactosidase, recombinant, EIA Grade
from E. coli overproducer, lyophilizate
For further processing only.
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β-Galactosidase, recombinant, EIA Grade material number and pack size: Material Number Pack Size 10570079103 custom fill
- Marker enzyme for the manufacturing of antibody- and antigen-enzyme conjugates incorporated in immunoassays for colorimetric and fluorimetric detection.
Molecular weight (by sequence): 465 kD
Structure: 4 identical subunits, β-galactosidase contains no carbohydrates
Isoelectric point: 4.61
Tris buffer, pH 7.6, +20°C / relation rate:
2-nitrophenyl-β-galactoside: 9.50 x 10-4 mol/L / 1.00
phenyl-β-D-galactoside: 3.23 x 10-3 mol/L / 0.05
lactose: 3.85 x 10-2 mol/L / 0.06
4-nitrophenyl-β-galactoside: 4.45 x 10-4 mol/L / ~0.50
Activators: Mg2+ and Na+ (or other monovalent cations) are essential for activity.
pH optimum: 8.0
pH stability: 6.0
Thermal stability: Up to +37°C
Thiol groups: 64 SH groups, approximately 16 of these are accessible for SH-reactive reagents. 4 of these (Cys 76) take part in conjugation. Appearance: White lyophilizate, stabilized with phosphate buffer and sucrose
Solubility: Clear, colorless solution in water (c=20 mg/mL)
Protein (Biuret): Approximatly 0.25 mg/mg lyophilizate
Specific activity (+37°C, 2-nitrophenyl-β-D-galactopyranoside): ≥700 U/mg protein
SH-groups, free (after dialysis): ≥12 mol/mol enzyme (corresponds to 465,000 g)
Aggregated β-galactosidase (HPLC): ≤3 area% (dimer-part with a molar mass of 0.93 x 106 D)
Stability: At -15 to -25°C within specification range for 24 months. Store under nitrogen.