A single-photon imaging system for the simultaneous quantitation of luminescent emissions from multiple samples.
A combination of a two-dimensional photon detector (double-microchannel plate) with single-photon sensitivity and an optical projection system that allows space-resolved quantitation of luminescent emissions from spatially extended objects is described. A "luminescent image" of the object focused onto the detector is accumulated over a preset time and stored in a digital frame memory from which photon counts over areas of interest can be read. In this study, the object consisted of a microtiter plate containing luminescent samples which was placed below a projecting lens (2.0/21 mm, 36 X 24-mm format camera lens) at a distance of 38.5 cm. Although geometry substantially limited photon collection, the sensitivity achieved was only 10X less than that obtained with a dedicated photon-counting luminometer. A slightly diminished photon collection from peripheral wells was apparently caused by the projection system and could be corrected arithmetically. Both chemically generated luminescence (ATP bioluminescence) and cell-derived, superoxide-dependent luminescence (with lucigenin as chemilumigenic probe) were detected with excellent spatial resolution and linearity of response over a wide range.
Maly
F E
FE
Institute of Clinical Immunology, Inselspital, Bern, Switzerland.
Urwyler
A
A
Rolli
H P
HP
Dahinden
C A
CA
De Weck
A L
AL
D000255:Adenosine Triphosphate / Q000494:pharmacology; D006098:Granulocytes / Q000032:analysis; D008163:Luminescent Measurements; D010783:Photometry; D011827:Radiation
D000255:Adenosine Triphosphate