Abstract: A method of quantifying glucose in a solution characterized in that electric potential measurement is conducted by potentiometry using a glucose dehydrogenase that requires a flavin compound as a coenzyme. It is preferable to carry out the quantification using a glucose dehydrogenase derived from a filamentous fungus, in particular derived from Aspergillus oryzae or Aspergillus terreus.

Abstract: [Problems] To provide a method which comprises detecting phosphorylation of substrate peptides with a quick and easy scheme using an inexpensive substance without a need for a special technique and which among other things enables comprehensive profiling kinetics of various protein kinases. [Means for Solving Problems] A method for analysis of protein kinase activity by detecting phosphorylation of at least one peptide which serves as a substrate for at least one protein kinase and is immobilized on the metal thin film in a basal plate of an array, characterized in that, in detecting the phosphorylation, the phosphorylated peptide is treated with a polyamine-zinc complex represented by, e.g., formula (I) which has a molecular weight of 500 to 1,000 and is modified with biotin and then preferably with avidin or streptavidin.