Quantitate beta-lactamase activity with GeneBLAzer Substrate Loading Kits

GeneBLAzer Substrate Loading Kits provide you a variety of FRET or Fluorescence Intensity-based substrates for reliable quantitation of beta-lactamase activity. Use in combination with CellSensor Cell Lines, CellSensor Reporter Vectors, and the GeneBLAzer Validated Functional Assays for GPCRs and NRs.

In addition to the dual-color readout of positive and negative cells, FRET-based substrates offer the advantage of ratiometric data analysis. Ratiometric methods eliminate well-to-well differences in cell number and substrate concentration caused by variations in hand pipetting or liquid handling instrumentation. Ratiometric methods also reduce or eliminate variations caused by excitation path length, fluorescence detectors or volume changes. These variations contribute to experimental noise and can mask the underlying biological response of interest.

Our broad range of substrates and assay formats provide you with the optimal choice for your experimental objectives and preferences.

Recommended GeneBLAzer Substrate Loading Kit By Application  

LiveBLAzer-FRET B/G Substrate Loading Kits

Ratiometric, live cell β-lactamase quantitation

LiveBLAzer-FRET B/G Loading Kits provide reliable, ratiometric detection of beta-lactamase activity in live cells. The blue/green ratio provides a normalized reporter response with smaller %CVs than single channel readouts. Each substrate consists of two fluorophores that form an efficient FRET pair, which in the absence of beta-lactamase activity results in a green fluorescence signal at 518 nm. In the presence of beta-lactamase activity, cleavage of the substrate disrupts FRET, resulting in a blue fluorescence signal at 447 nm. The blue signal can be readily observed under a microscope and can also be detected on bottom-read fluorescent microplate readers.

The LiveBLAzer-FRET B/G Loading Kit:

  • Reduces false hits by minimizing experimental noise with the ratiometric blue/green readout
  • Enables rapid development of stable cell lines using flow cytometry
  • Facilitates miniaturization and measurement of small biological responses due to high sensitivity
  • Minimizes sample handling and increases throughput with a homogeneous format
Population of CHO-K1 cells expressing β-lactamase as measured by LiveBLAzer- FRET B/G Substrate
This live cell microscopy image shows a population of CHO-K1 cells expressing β-lactamase as measured by LiveBLAzer- FRET B/G Substrate.

ToxBLAzer DualScreen Loading Kits

Ratiometric, live cell beta-lactamase quantitation with cytotoxicity indicator

The ToxBLAzer DualScreen Assay combines the advantages of LiveBLAzer™-FRET B/G with a cytotoxicity indicator in a single assay format. The readout allows you to identify false positives due to cytotoxic compounds, which is critical in screening applications which down-regulate transcription or when there is a lack of viable cells. The cytoxicity indicator fluorescence is red-shifted to ensure compatibility with the blue and green emission of the LiveBLAzer-FRET B/G Substrate, allowing detection of both beta-lactamase activity and the cytotoxicity readout in the same well (see figure below).

The ToxBLAzer DualScreen Assay:

  • Provides rapid identification of false positives due to toxicity or lack of viable cells
  • Reduces false hits by minimizing experimental noise with the ratiometric blue:green reporter readout
  • Eliminates need for follow-up cytotoxicity assays by multiplexing the reporter readout with a cytoxicity readout
Population of cells expressing beta-lactamase as measured by LiveBLAzer™-FRET B/G substrate
A. This live cell microscopy image shows a population of cells expressing beta-lactamase as measured by LiveBLAzer-FRET B/G Substrate.
B. The same population of cells analyzed with beta-lactamase reporter activity are shown with the red emission.

LyticBLAzer Loading Kits

LyticBLAzer Substrates provide an end-point method for analyzing beta-lactamase activity in cell lysates using any fluorometer. By combining the components for lysis and detection in a single reagent addition, the LyticBLAzer Substrates provide a very simple assay. They are available in two detection formats: ratiometric (FRET) or fluorescence intensity (FI) based on the BODIPY dye. Complete LyticBLAzer Substrate Kits are available in homogeneous as well as non-homogeneous assay formats, each optimized for a different assay condition (see figure below).

LyticBLAzer Substrate Kits:

  • Enable quantitation of beta-lactamase activity on top-read or bottom-read fluorescence instrumentation
  • Reduce false hits by minimizing experimental noise using LyticBLAzer-FRET B/G Ratiometric (blue:green) reporter readout
  • Minimize fluorescence interference caused by sample contaminants such as dust and lint using LyticBLAzer-BODIPY FL dye
  • Provide long read times with stable fluorescence


For Research Use Only. Not for use in diagnostic procedures.