Sigma-Aldrich Beta-Lactamase Activity Assay Kit. sufficient for 200 colorimetric tests. 1 kit

β-Lactamases are a large family of enzymes capable of hydrolyzing β-lactams. A β-Lactam ring is the common element in all beta-lactam antibiotics including penicillin derivatives, cephalosporins, monobactams, and carbapenems. Through hydrolysis, β-lactamase breaks the β-lactam ring open, deactivating the antibacterial properties. Bacteria from clinical and non-clinical settings are becoming increasingly resistant to β-lactam antibiotics by synthesizing β-lactamase. To overcome this resistance, β-lactam antibiotics are often given with β-lactamase inhibitors such as clavulanic acid. Therefore, detection of β-lactamase activity is of central importance to assess beta-lactam antibiotics as well as to prevent antibiotics resistance.

The Beta-Lactamase Activity Assay Kit offers a sensitive colorimetric assay for measuring β-lactamase activity in biological samples. The assay can be performed using an absorbance microplate reader by measuring the OD ratio at the wavelength of 490 nm to 380 nm.

The β-lactamase activity is detected using nitrocefin, which changes color from yellow to red upon hydrolysis by β-lactamase.



One unit of β-lactamase is the amount of enzyme required to hydrolyze 1.0 µmole of nitrocefin per minute at pH 7.0 at 25°C.