luciola have been known to live in japan as a result of the following experiments conducted to genji firefly scientific name luciola cruciata the name of luciferase will be referred to as genji in the present specification the gene arrangement thereof being already known differences in km value were found out the present invention has taken notice of this differences in km value and hence one of important subject matters of the present invention is to utilize the luciferase as a luminescent marker in conformity with purposes first of all in order to calculate the concentration of d luciferin the ultraviolet visible light absorption spectrum of d luciferase was measured in this measurement the spectrum was measured using a diluted by 4000 times solution in 0 1m citrate 0 2m na 2 hpo 4 buffer ph 5 0 of d luciferin promega co ltd stock solution about 100 mm as for the blank the buffer described above was employed fig6 illustrates the ultraviolet visible light absorption spectrum of d luciferase by making use of the absorbency 328 nm 0 467 u00b1 0 006 n 10 obtained from the spectrum of fig6 the concentration of the d luciferin stock solution was calculated d luciferin u03bbd max 328 nm u03b5c 18200 ph 5 0 as a result of the calculation the concentration of the d luciferin stock solution was found as being 102 6 mm then in order to calculate the concentration of atp the ultraviolet visible light absorption spectrum of atp was measured in this measurement the spectrum was measured using a diluted by 2000 times.