Patent ID: 8486712

Claim:
A deuterium isobaric tag reagent (DiART) reagent comprising the formula: reporter group−balancer group−reactive group wherein the reporter group comprises (CH 3 ) 2 —CH—CH 2 —CH—(N(CH 3 ) 2 ), the balancer group comprises CO—(NH)—CH 2 —CH 2 —CO, the reactive group comprises cyclo-N(CO—CH 2 —CH 2 —CO)—O, and the reagent has the structure: wherein the reporter group and the balancer group are linked by a MS/MS scissionable bond, the reporter group comprises 0 to 9 heavy isotope atoms selected from 13 C, 15 N and 2 H, the balancer group comprises 0 to 9 heavy isotope atoms selected from 13 C, 15 N and 2 H, the reagent contains 1 to 6 2 H atoms, and wherein the CH 3 at position 1 comprises 0 to 3 2 H atoms and the C is selected from 12 C and 13 C, the CH 3 at position 2 comprises 0 to 3 2 H atoms and the C is selected from 12 C and 13 C, the N at position 3 is selected from 14 N and 15 N, the C at position 4 is selected from 12 C and 13 C, the N at position 5 is selected from 14 N and 15 N, the CH 2 at position 6 comprises 0 to 2 2 H atoms and the C is selected from 12 C and 13 C, the CH 2 at position 7 comprises 0 to 2 2 H atoms and the C is selected from 12 C and 13 C, the C at position 8 is selected from 12 C and 13 C; and wherein the mass of the reporter group is 114-123 Daltons, the mass of the balancer group is 99-108 Daltons, and the sum of the mass of the reporter group and the balancer group is 214-222 Daltons.