Comparison of Photon Counting Devices Using Antibiotics and Heavy Metal Biosensors

Abstract

Bioluminescence has been of great interest for the past few decades. There have been plenty of biotechnological methods to detect, estimate, view and establish the bioluminescence obtained from variety of organisms. Due to the advancements in genetic engineering technologies, increasing number of instruments has been manufactured for the detection and counting of bioluminescence. However, very few studies have been reported comparing the efficiency and working of different photon counting instruments available today. Henceforth, special effort has been taken to study and compare the photon counting devices in this thesis. The aim of the thesis is to compare three different photon counting devices available at the laboratory of environmental engineering and biotechnology; namely Chameleon Multilabel plate reader from Hidex Oy, Victor2 Wallac from Perkin Elmer life sciences and IVIS Lumina Xenogen from Caliper Life Sciences. The efficiency of these three devices were compared by using two different bacterial strains, one is bioluminescent whole-cell biosensor strain, Escherichia coli DPD2794 and the other being an arsenic biosensor strain Escherichia coli XL-1(parsRluxCDABE). These Genetically engineered bacterial strains have been grown under laboratory conditions and comparative luminescence was done by bioluminescence measurement methods and agar diffusion method (bio-photonic imaging station). Inducible ciprofloxacin with different concentrations were used for Escherichia coli DPD2794 and arsenite NaAsO2 (III) and arsenate Na2HAsO4 (V) were used as a biosensor for detecting the amount of bioluminescence emitted from respective bacterial species. On comparing the efficiency of bioluminescence detected by three different photon counting devices, Chameleon was found to provide most sensitive and IVIS the lowest. However all the approaches is useful depending upon the application employed. /Kir11