Luminometer apparatus
First Claim
1. A luminometer apparatus including circuit means comprising a photodetector arranged to detect light emission from a phosphorescent reaction exhibiting a peak light value, means for predeterminedly shielding said photodetector from light, means arranged to sample the light emission from the phosphorescent reaction detected by the photodetector at predetermined time intervals when the shielding means is not shielding the photodetector, subtracting means connected to said sample means for subtracting the sampled light emission of consecutive samples and for determining the peak light value, means for moving the shielding means to shield said photodetector so as to detect the dark current of the photodetector after the peak light value has been determined and said subtracting means operable for subtracting the dark current from said peak light value to determine a true intensity of the peak light value.
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Accused Products
Abstract
A luminometer apparatus has a light-tight box (12) into which a cuvette (2) containing a sample and a reagent are located for producing a phosphorescent reaction. The phosphorescent reaction is detected by a photodetector (PD) and a shutter (3) is interposed between the cuvette and the shutter. Output signals from the photodetector are applied to a circuit arrangement (FIG. 4) which detects the phosphorescent reaction at predetermined intervals and by subtracting the successive values of light from one another so a measured peak value of light intensity is determined. The shutter is closed and the dark current signal of the photodetector is determined and subtracted from the measured peak value. A true peak intensity of the emitted light is thus derived and the concentration of the material being assayed is calculated by raising the peak intensity to the power n where n has a value between 0 and 9 predeterminedly derived for the sample.
41 Citations
11 Claims
- 1. A luminometer apparatus including circuit means comprising a photodetector arranged to detect light emission from a phosphorescent reaction exhibiting a peak light value, means for predeterminedly shielding said photodetector from light, means arranged to sample the light emission from the phosphorescent reaction detected by the photodetector at predetermined time intervals when the shielding means is not shielding the photodetector, subtracting means connected to said sample means for subtracting the sampled light emission of consecutive samples and for determining the peak light value, means for moving the shielding means to shield said photodetector so as to detect the dark current of the photodetector after the peak light value has been determined and said subtracting means operable for subtracting the dark current from said peak light value to determine a true intensity of the peak light value.
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6. A luminometer apparatus including circuit means comprising a photodetector arranged to detect light emission from a phosphorescent reaction exhibiting a peak light value, means for predeterminedly shielding said photodetector from light, means arranged to sample the light emission from the phosphorescent reaction detected by the photodetector at predetermined time intervals when the shielding means is not shielding the photodetector, subtracting means connected to said sample means for subtracting the sampled light emission of consecutive samples and for determining the peak light value, means for moving the shielding means to shield the photodetector so as to detect the dark current of the photodetector after the peak light value has been reached, said subtracting means operable for subtracting the dark current from said peak light value, a microprocessor for determining the concentration of an analyte which is reacted with a reagent, said microprocessor calculating In, where I is the true peak light value and n is a variable between 0 and 9, and input means for inputting n to the microprocessor.
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7. A method of determining the peak light value of a phosphorescent reaction by the steps of using a photodetector to detect the light signal output from the phosphorescent reaction at predetermined time intervals, subtracting successive light output signals from one another, determining when the difference between successive light output readings falls below a predetermined minimum value to thereby determine the peak signal, determining the signal produced by the photodetector when no light falls thereon, and subtracting said produced signal from the peak signal to derive the true intensity of the peak light value.
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11. A method of determining the peak light value of a phosphorescent reaction by the steps of using a photodetector to detect the light signal output from the phosphorescent reaction at predetermined time intervals, subtracting successive light output signals from one another, determining when the difference between successive light output readings falls below a predetermined minimum value to thereby determine the peak signal, determining the signal produced by the photodetector when no light falls thereon, subtracting said produced signal from the peak signal to derive the true intensity of the peak light value, and determining the concentration of an analyte which is reacted with a reagent by calculating In where I is the true peak light value and n is an inputted value between 0 and 9.
Specification