The invention relates to a method of identifying or producing an aptamer, the method comprising the steps of: a) Providing a candidate mixture of nucleic acids; b) Contacting the candidate mixture with a target sample; c) Partitioning nucleic acids that bind to the target sample from those that do not bind; d) Amplifying the binding nucleic acids to produce a population of nucleic acids that bind the target sample; e) Single strand displacement of the amplified nucleic acids, f) optionally repeating the steps a) to e), thereby identifying or producing an aptamer, wherein the target sample provides one or more peptides and/or proteins in a denatured form.

An aptamer-based switch technology is provided that enhances control of the use of chimeric antigen receptor (CAR)-related immunotherapies. The aptamer-based switch utilizes a synthetic bridge molecule containing a target-binding aptamer bound through a linker to a CAR-binding aptamer. A system containing a CAR and a corresponding aptameric bridge provides an immunotherapy platform that: (i) can be targeted to any desired antigen by choosing the target-binding aptamer of the bridge, (ii) can be redirected from one target to another by changing the target-binding aptamer; (iii) can be dosed according to the changing needs of an individual patient overtime by altering the administration protocol for the bridge; (iv) can be switched on or off quickly or gradually; (v) can be used as a companion diagnostic for a specific CAR therapy; (vi) can be integrated with either in vivo or ex vivo CAR expression; (vii) is non-immunogenic; and (viii) has low production costs.

Devices for detecting at least one target molecule in a sample are provided. The devices comprise a field-effect transistor and an aptamer attached to the field-effect transistor. The aptamer comprises a capture region and a stem region, wherein the target molecule can selectively bind to the capture region of the aptamer. The stem region can change a conformation of the aptamer when the capture region binds to the target molecule. Techniques for detecting a target molecule using such devices are also provided.

Methods of selecting an aptamer that specifically binds to a target molecule complexed with a derivatization agent. Also disclosed are specific aptamers and methods of use thereof.

The present disclosure describes compositions and methods for rapid selection of both binding and functional oligonucleotides (DNA, RNA, or any natural or synthetic analog of these). In certain embodiments, provided herein are flow cells (e.g., flow cells for an Illumina sequencing instrument or a Polonator sequencing instrument) comprising within its flow chamber a plurality of immobilized aptamer clusters (e.g., from an aptamer library described herein) and, optionally, one or more target cells (e.g., cancer cells, immune cells, etc.) and/or a detectable indicator of cellular function (e.g., a fluorescent indicator of apoptosis, cell proliferation, gene or protein expression, etc.). In certain embodiments, provided herein are methods of using such an aptamer cluster-containing flow cell to identify functional aptamers from an aptamer library (e.g., in a sequencing instrument, such as an Illumina sequencing instrument).

The present disclosure provides methods, kits and compositions for identifying nucleic acid agents having a desired property, e.g., a property of specifically binding to a target (such as a protein target) with high affinity. More specifically, the present disclosure provides methods, kits and compositions for identifying candidate nucleic acid agents with both high specificity and affinity for a target.

Disclosed herein are compositions including an aptamer bound to a complex, wherein the complex comprises at least two polypeptides. Also disclosed are methods of quantifying a fraction of PD1 occupied by PDL1 or a fraction of PDL1 occupied by PD1 in a sample, and methods of isolating complexes using aptamers that are capable of binding to the complex.

Described herein is a reversible aptamer selection technology for production-scale isolation of label-free cells (e.g., CD8+ T cells). Provided herein are methods for isolating a cell of interest from a biological sample by contacting the biological sample with an aptamer that specifically binds a cell surface marker specific for the cell of interest; separating the aptamer-bound cells from cells not bound to the aptamer; and recovering a cell of interest by disrupting binding of the aptamer to the cell surface marker.

Compositions comprising aptamers capable of specifically binding to a surface protein of Clostridium difficile spore are provided. A method for detecting, enriching, separating, and/or isolating Clostridium difficile spores is provided.

A method of producing an aptamer selectively binding a non-canonical structure of a target nucleic acid molecule includes the steps of: incubating a plurality of nucleic acid sequences with an enantiomer of the non-canonical structure under suitable conditions to obtain one or more candidate nucleic acid sequences binding to the enantiomer of the non-canonical structure, purifying and amplifying the one or more candidate nucleic acid sequences; repeating said incubating, purifying and amplifying steps for a predetermined number of cycles under different conditions; and producing an enantiomer for selected amplified candidate nucleic acid sequence to obtain the aptamer capable of selectively binding the non-canonical structure of the target nucleic acid molecule. An aptamer selectively binding to a non-canonical structure of a nucleic acid molecule or its enantiomer, the aptamer comprising a sequence of SEQ ID NO: 11; as well as uses of the aptamer or its enantiomer.