Abstract: A DC power supply circuit outputs an output voltage, which varies with an input voltage. The output voltage therefore occasionally deviates from a normal output voltage range although the DC power supply circuit is normal. However, the DC power supply circuit converts the input voltage in a predetermined relation between the input voltage and the output voltage. When the output voltage of the DC power supply circuit deviates from a predetermined normal output voltage range, a determination circuit determines that the DC power supply circuit is abnormal when the input voltage and the output voltage of the DC power supply circuit are not in the predetermined relation. It is thus prevented that the DC power supply circuit is erroneously determined to be abnormal although operating normally. As a result, it is possible to eliminate erroneous determination in determining the operation state itself.

Abstract: A DC power supply circuit outputs an output voltage, which varies with an input voltage. The output voltage therefore occasionally deviates from a normal output voltage range although the DC power supply circuit is normal. However, the DC power supply circuit converts the input voltage in a predetermined relation between the input voltage and the output voltage. When the output voltage of the DC power supply circuit deviates from a predetermined normal output voltage range, a determination circuit determines that the DC power supply circuit is abnormal when the input voltage and the output voltage of the DC power supply circuit are not in the predetermined relation. It is thus prevented that the DC power supply circuit is erroneously determined to be abnormal although operating normally. As a result, it is possible to eliminate erroneous determination in determining the operation state itself.

Abstract: A light reception section receives fluorescence emitted according to the amount of target nucleic acid that has been amplified by PCR due to a light source illuminating excitation light onto a reaction liquid. Electrical signals from the light reception section whose level depends on the received fluorescence intensity are amplified by plural amplification circuits having different amplification factors. A multiplexor selects an electrical signal amplified with an amplification factor in an initial stage of an amplification reaction and detects a fluorescence value for that cycle. A CPU acquires the largest fluorescence value in the initial stage and determines the amplification factor for a corrected stage and inputs a selection signal to the multiplexor to select the electrical signal amplified by the determined amplification factor. In the corrected stage the electrical signal amplified with the determined amplification factor is selected and fluorescence values detected.

Abstract: A nucleic acid abundance ratio measurement device includes a detection section that detects a detection signal over different temperature ranges of a melting curve for a nucleic acid mixture having one or more melting temperatures, and an abundance ratio computation section that computes a nucleic acid abundance ratio based on a ratio of characteristic amounts obtained from the detection signal detected by the detection section and based on detection amount data.