Somatic hypermutation promotes affinity maturation of antibodies by targeting the cytidine deaminase AID to antibody genes, followed by antigen-based selection of matured antibodies. Given the importance of antibodies in medicine and research, developing approaches to reproduce this natural phenomenon in cell culture is of some interest. The inventors use here the CRISPR-Cas 9 based CRISPR-X approach to target AID to antibody genes carried by expression vectors in HEK 293 cells. This directed mutagenesis approach, combined with a highly sensitive antigen-associated magnetic enrichment process, allowed rapid progressive evolution of a human antibody against the Human Leucocyte Antigen A*0201 allele. Starting from a low affinity monoclonal antibody expressed on Ag-specific naïve blood circulating B cells, they obtained in approximately 6 weeks antibodies with a two log increase in affinity and which retained their specificity. The strategy for in vitro affinity maturation of antibodies is applicable to virtually any antigen. It not only allows to tap into the vast naive B cell repertoire but could also be useful when dealing with antigens that only elicit low affinity antibodies after immunization. Accordingly as defined by the claims, the present invention relates to methods and kits for generating and selecting a variant of antibody binding protein with increased binding affinity and/or specificity.

The present invention relates inter alia to aptamers that specifically bind to Imatinib and methods of using the same.

The present disclosure describes compositions and methods for selection functional aptamers. In certain embodiments, provided herein are methods of using aptamer cluster-containing particles to identify functional aptamers from an aptamer library. In certain embodiments, provided herein are functionally enriched populations of aptamers. In certain embodiments, provided herein are methods for selecting an aptamer for use in personalized cancer treatment and methods for preparing a tumor delivery system. In certain embodiments, provide herein are compositions comprise the aptamer cluster-containing particles, 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.).

Disclosed is a method of sequencing a nucleic acid containing an unnatural base pair (UBP), comprising performing two or more replacement replication reactions wherein the nucleic acid is replicated using two or more intermediate of the unnatural base pair; sequencing the nucleic acid resulting from the replacement replication reactions; clustering the sequenced nucleic acid and identifying a candidate position of the unnatural base pair; determining a ratio of conversion of the intermediate to each one of a natural base pair at the candidate position of the unnatural base pair; comparing the ratio of conversion of the intermediate to a library of pre-determined conversion rate based on the sequences of one or more natural base pair adjacent to the candidate position of the unnatural base pair; wherein a substantial match of the ratio of conversion of the intermediate to a value in the library of the pre-determined conversion rate confirms the position of the unnatural base pair, thereby determining the sequence of the nucleic acid containing the unnatural base pair. Also disclosed is an apparatus for performing the method as disclosed herein.

The present disclosure relates to novel DNA aptamers and use thereof. In particular, the present disclosure relates to DNA aptamers selected from a DNA library using Cell-SELEX to bind specifically to cancer cells. The DNA aptamers of the present disclosure selected and optimized for high binding affinity to cancer cells can be effectively used for the diagnosis of cancer as they have enhanced targeting efficiencies for target cells and tissues as well as high serum stability.

The present disclosure relates to methods for identifying aptamers against allergen proteins and signaling polynucleotides (SPNs) for allergen detection. The screening method of the present disclosure combines several positive SELEX selections, and on-chip positive and counter selections to identify aptamer sequences that are preferentially bind to target proteins when competing with short complementary sequences.

The present disclosure provides an anti-Ang2 aptamer, a bispecific molecule or a composition comprising the anti-Ang2 aptamer, as well as uses thereof.

The disclosure is directed to methods and compositions for screening a library of aptamers for aptamers having a binding affinity to a target molecule. Specifically, non-natural nucleotides can be introduced onto aptamers immobilized on the surface of beads. The non-natural nucleotides can then be subsequently chemically modified to include additional binding agents. For example, copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions can be used to introduce a wide range of binding agents onto non-natural nucleotides on beads.

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.

The disclosure is directed to methods and compositions for screening a library of aptamers for aptamers having a binding affinity to a target molecule. The methods and compositions described herein utilize a throughput approach that is able to simultaneously measure binding affinity and link the binding affinity to the identity (e.g., sequence) of the aptamer.