Aqueous solution may be used directly for derivatization without previous dialysis or gel permeation chromatography.
β-半乳糖苷酶可将乳糖切割成单糖成分（葡萄糖和半乳糖）。它还在反馈环中催化葡萄糖转糖基化为β-半乳糖苷酶的诱导物 - 异乳糖。
Bottomless glass bottle. Contents are inside inserted fused cone.
四聚体的分子量为465 kDa（每个亚基116.3 kDa）
1 U corresponds to the amount of enzyme which hydrolyzes 1 μmol 2-nitrophenyl-β-D-galactopyranoside (Cat. No. 73660) per minute at pH 7.8 and 37 °C
Used in a highly sensitive enzyme-linked immunoassay of human IgG with 4-methylumbelliferyl-β-D-galactoside (Catalog No. 69590); Evaluation of β-D-galactosidase (E. coli) and horse radish peroxidase as labels by sandwich enzyme immunoassay technique; Enzyme immunoassay of thyrptropin releasing hormone (TRH); Preparation of enzyme-antibody conjugates