id,target_name_canonical,target_type,target_uniprot,aptamer_name,aptamer_seq,kd_reported,kd_log10_molar,measurement_class,binding_constant_type,tier,source_origin,verification_level,sequence_status,seq_source,pi_provenance_flag,assay_method,assay_temperature_k,assay_ph,assay_buffer,assay_cations,aptamer_chemistry,aptamer_modifications,source_pmid,doi,verbatim_quote,source_db 465,SARS-CoV-2 spike RBD,protein,,Aptx2-L,,4.900000000000001e-09 M,-8.31,avidity_multivalent,Kd,Gold,v4,multi_agent_verified,pending_manual_supp,,,flow_cytometry,298.15,7.4,"PBS, pH 7.4, 0.55 mM MgCl2",,DNA,,41498844,10.1021/acsami.5c16490,The Aptx2-L variant showed superior affinity with a dissociation constant ( K d) of 4.9 nM,step2c_acs_v1 466,SARS-CoV-2 spike RBD,protein,,Aptx2-S,,2.17e-08 M,-7.664,avidity_multivalent,Kd,Gold,v4,multi_agent_verified,pending_manual_supp,,,flow_cytometry,298.15,7.4,"PBS, pH 7.4, 0.55 mM MgCl2",,DNA,,41498844,10.1021/acsami.5c16490,compared to 21.7 nM for Aptx2-S,step2c_acs_v1 442,PTK7,protein,Q13308,Sgc8c-Si6,,5.7230000000000004e-08 M,-7.242,apparent_cellular,Kd,Gold,v4,multi_agent_verified,pending_manual_supp,,,flow_cytometry,277.15,,washing buffer supplemented with 1 mg/mL BSA and 1 mM yeast tRNA,,DNA,poly-Si,40415219,10.1021/acs.analchem.5c01062,Sgc8c-Si6 maintained strong binding affinity ( K d = 57.23 nM),step2c_acs_v1