University of California

Ying Ji

Roger Y Tsien

Huan Meng

Stephen R Adams

Xiangsheng Liu

Susan S Taylor

April D Pyle

Melissa J Spencer

Courtney S Young

Michael Reza Emami

In various embodiments a polyrotaxane carrier for in vivo delivery of a nucleic acid is provided. In certain embodiments the carrier comprises: a multi-arm polyethylene glycol (PEG) backbone comprising at least three arms; at least one cyclic compound having a cavity, where an arm of said multi-arm PEG backbone is threaded into the cavity of said cyclic compound forming an inclusion complex; a bulky moiety capping the terminal of the arm(s) threaded into said cyclic compound where said moiety inhibits dethreading of the cyclodextrin from the arm(s) of said backbone; and where at least one arm of said PEG backbone is free of cyclic compounds; and where said carrier has a net positive charge.

Multi-armed polyrotaxane platform for protected nucleic acid delivery

The invention provides labeled proteins suitable for determining the presence of cAMP, other second messengers and organic molecules. The proteins are separately labeled with fluorochromes which, when in close spatial proximity, preferably, less than about 6 nm, interact through the transfer of energy from one fluorochrome to the other. A composition of matter, (S.sub.1.A).sub.n1 (S.sub.2.D).sub.n2 is provided wherein S.sub.1 and S.sub.2 are two proteins which are associated in one state and substantially disassociated in another, the equilibrium between which is controlled by the free concentration of an analyte, and A and D are fluorochromes, the emission wavelength of fluorochrome D overlapping the excitation wavelength of fluorochrome A and the distance between A and D being in sufficiently close proximity to allow the radiationless transfer of energy between the fluorochromes. A and D can be selected from a variety of acceptor, donor pairs such as fluorescein and tetramethylrhodamine and derivatives thereof. The concentration of analytes such as cAMP in a sample can be determined by contacting the sample with (S.sub.1.A).sub.n1 (S.sub.2.D).sub.n2 providing energy near the excitation wavelength of D and measuring the fluorescence of A or D, the concentration of cAMP and other said analytes being determined by the ratio of emission of D to the emission of A, previously calibrated with reference solutions of known analyte concentration.

Detection of analytes using fluorescent energy transfer

Growing community of inventors

San Diego, CA, United States of America

Ying Ji