Multi-stage sample-recovery systems, including automated 2-stage and 3-stage sample-recovery systems, are provided. Such systems enable the rapid screening and recovery of samples, including viable cell-based samples, from high-throughput screening systems, including systems utilizing large-scale arrays of microcapillaries. In specific screening systems, each microcapillary comprises a solution containing a variant protein, an immobilized target molecule, and a reporter element. Immobilized target molecules may include any molecule of interest, including proteins, nucleic acids, carbohydrates, and other biomolecules. The association of a variant protein with a molecular target is assessed by measuring a signal from the reporter element. The contents of microcapillaries identified in the assays as containing variant proteins of interest can be identified and recovered using the multi-stage systems disclosed herein.

The invention relates to sensor compositions comprising a composite array of individual arrays, to allow for simultaneous processing of a number of samples. The invention further provides methods of making and using the composite arrays. The invention further provides a hybridization chamber for use with a composite array.

Methods are provided for producing a molecular array comprising a plurality of molecules immobilized to a solid substrate at a density which allows individual immobilized molecules to be individually resolved, wherein each individual molecule in the array is spatially addressable and the identity of each molecule is known or determined prior to immobilization. The use of spatially addressable low density molecular arrays in single molecule detection and analysis techniques is also provided. Novel assays and methods are also provided.

Multi-stage sample-recovery systems, including automated 2-stage and 3-stage sample-recovery systems, are provided. Such systems enable the rapid screening and recovery of samples, including viable cell-based samples, from high-throughput screening systems, including systems utilizing large-scale arrays of microcapillaries. In specific screening systems, each microcapillary comprises a solution containing a variant protein, an immobilized target molecule, and a reporter element. Immobilized target molecules may include any molecule of interest, including proteins, nucleic acids, carbohydrates, and other biomolecules. The association of a variant protein with a molecular target is assessed by measuring a signal from the reporter element. The contents of microcapillaries identified in the assays as containing variant proteins of interest can be identified and recovered using the multi-stage systems disclosed herein.