Abstract: A fluorescent probe for measuring magnesium ion, which can selectively form a complex with magnesium ion in aqueous system is disclosed. The fluorescent probe for measuring magnesium ion according to the present invention has the structure represented by the following Formula [I]: (wherein R1 represents a hydrogen atom, metal atom or an ester-forming group; A represents a group which forms a ring structure together with carbon atom 1 and carbon atom 2; and X is a fluorescent group which may form a condensed ring together with the ring containing the group A).

Abstract: A process for providing cDNAs containing full primary structure information of proteins by selectively synthesizing full-length cDNAs containing sequences starting from the capped region of mRNAs is disclosed. The invention provides a process for producing an intermediate for the synthesis of a full-length cDNA, which comprises the steps of treating mRNA extracted from cells to eliminate the phosphate group from the 5' end of an uncapped degraded mRNA; decapping from the 5' end of a capped intact mRNA; and ligating either a DNA oligonucleotide or a DNA-RNA chimeric oligonucleotide represented by the following general formula [I] to the 5' end phosphate group formed in the above step by the action of T4 RNA ligase, thereby selectively adding either the DNA oligonucleotide or the DNA-RNA chimeric oligonucleotide having an arbitrary sequence to the 5' end of the intact mRNA.5'-dN1-dN2- . . . -dNm-N1-N2- . . .