Abstract: Embodiments of a composition for stabilizing fluorescent signal of nanoparticles and methods for its use are disclosed. In some embodiments, the composition has a pH from 7 to 10 and includes borate, protein and/or protein hydrolysate, an amine, a preservative, and a nonionic surfactant. In particular embodiments, the amine is an N-ethanol substituted amine, such as ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N,N-dimethylethanolamine, or a combination thereof. In some embodiments, a fluorescent particle solution, such as a quantum dot solution or quantum dot conjugate solution, is diluted in the composition and stored at 4° C. In certain embodiments, the fluorescence intensity of the diluted fluorescent particle remains substantially the same when stored at 4° C. for at least one month or at least three months. In particular embodiments, a diluted quantum dot conjugate is used to detect a hybridized probe or a protein antigen.

Abstract: Embodiments of a composition for stabilizing fluorescent signal of nanoparticles and methods for its use are disclosed. In some embodiments, the composition has a pH from 7 to 10 and includes borate, protein and/or protein hydrolysate, an amine, a preservative, and a nonionic surfactant. In particular embodiments, the amine is an N-ethanol substituted amine, such as ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N,N-dimethylethanolamine, or a combination thereof. In some embodiments, a fluorescent particle solution, such as a quantum dot solution or quantum dot conjugate solution, is diluted in the composition and stored at 4° C. In certain embodiments, the fluorescence intensity of the diluted fluorescent particle remains substantially the same when stored at 4° C. for at least one month or at least three months. In particular embodiments, a diluted quantum dot conjugate is used to detect a hybridized probe or a protein antigen.

Abstract: This invention provides methods and compositions useful for identifying and diagnosing rare fetal cells in a mixed cell population such as a maternal blood sample. The methods entail the use of specific nucleic acid probes that hybridize to fetal cell associated RNAs to identify the rare fetal cells or antibodies that bind to polypeptides encoded by the fetal cell associated RNAs for fetal cell detection. The cells detected by the methods of the present invention are useful for diagnosing the fetal cells for a genetic trait of interest, such as trisomy 21. Novel methods for simultaneous screening for fetal cells and diagnosing the fetal cells are also provided. Compositions comprising the fetal cell associated nucleic acids of the invention and their encoded proteins are also provided. The present invention further provides kits useful for practicing the present methods.

Abstract: This invention provides methods and compositions useful for identifying and diagnosing rare fetal cells in a mixed cell population such as a maternal blood sample. The methods entail the use of specific nucleic acid probes that hybridize to fetal cell associated RNAs to identify the rare fetal cells or antibodies that bind to polypeptides encoded by the fetal cell associated RNAs for fetal cell detection. The cells detected by the methods of the present invention are useful for diagnosing the fetal cells for a genetic trait of interest, such as trisomy 21. Novel methods for simultaneous screening for fetal cells and diagnosing the fetal cells are also provided. Compositions comprising the fetal cell associated nucleic acids of the invention and their encoded proteins are also provided. The present invention further provides kits useful for practicing the present methods.