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12th International Symposium on Bioluminescence & Chemiluminescence |
Symposium abstracts:
Coates, Colin G., Denvir, Donal
Andor Technology Ltd., 9 Millennium Way, Springvale Business Park, Belfast,
Email:c.coates@andor-tech.com
Ultrasensitive detection of low concentrations of chemiluminescent biomarker (Horse Radish Peroxidase/luminol) has been performed using an imaging Electron Multiplying Charge Coupled Device (EMCCD). For these experiments, serial dilutions of biomarker were placed either within the wells of high density microtitre plates or spotted onto microarray chips. Camera exposure times were kept sufficiently short in order that the lowest concentrations should be undetectable under ‘normal’ CCD operation. However, the EMCCD is an imaging sensor with photon counting ability, achieved by way of a unique electron multiplying structure built into the silicon, rather than the incorporation of an image intensifier tube. Importantly, the camera sensitivity is not limited by the restricted quantum efficiency otherwise imposed by intensifier tubes of ICCDs, enabling the combined advantages of both tunable amplification and the unimpaired harnessing of the higher/broader QE curves of the CCD chips. In these experiments, gain was varied from unity upwards, to a degree where the extremely weak signals from the lowest concentration wells or spots could be detected above the associated noise. Such demonstrations of remarkable sensitivity amplification/control suggest application within many areas of ultrasensitive analysis, uniquely facilitating the developing trend towards detection of single molecules.
This
is a preprint of an article accepted for publication in Luminescence: Copyright
2001 John
Wiley & Sons, Ltd (Wiley website)