Easily identify specific targets with these antibody alternatives

Aptamers are oligonucleotides or peptides that bind to a specific target molecule with high specificity and affinity. Although occurring naturally as part of a riboswitch, aptamers can also be engineered through repeated rounds of in vitro selection, and are able to bind to various molecular targets such as small molecules, proteins, nucleic acids, and cells.

Aptamers vs. Antibodies

Aptamers are extremely useful in a range of biotechnological and therapeutic applications, and offer many advantages over antibodies:

ProductionChemical synthesis Cell culture and need for animals
Discovery time 8 weeks ̴ 6 months
StabilityStable in harsh conditions Potential loss of function in harsh conditions
AssaysNo secondary reagent is needed Secondary antibody is needed
ModificationEasy to chemically modify Difficult to chemically modify
SizeSmall size (<30KDa)Large size ( ̴ 150KDa)

Aptamer Identification

The unique secondary and tertiary structures of aptamers provide the specificity to detect even small structural changes in the target molecule, including the presence or absence of methyl or hydroxyl groups or differences in enantiomeric configurations.

Aptamers that bind specific targets are identified through a process known as Systematic Evolution of Ligands by Exponential enrichment (SELEX) in which binding molecules are selected from a large and diverse library of nucleic acids (either DNAs or RNAs). In this process, the nucleic acid library is incubated with the target molecule. Non-binding nucleic acids are then washed away, leaving behind only the molecules that have a capacity to bind to the target molecule.

The nucleic acids that are not washed away are then used to create a new library of nucleic acids that is enriched for the subset that binds the desired target. Repeating this selection-cycle on each subsequent library with increasing stringency of binding (e.g. lower concentration of target), ensures that nucleic acids that bind to the target with both high specificity and high affinity are enriched.

Available Aptamer Targets

Target Proteins (human)Kd(nM)Target Proteins (human)Kd(nM)
ACVR1A / ALK-235L-Selectin / CD62L4.57
ACVR1B / ALK-4 / Actin RIB / SKR215MERTK / MER8.82
ACVR2A / Act R-IIa1.41MPL / CD110 / TpoR1.81
ACVRL12.09Mre11 & Rad50*0.17
Akt1 / PKB alpha*0.5NCAM-1 / CD562.12
Akt2 / PKB beta*4.48NGF R / TNFRSF1617.84
Akt3 / PKBG*0.69NLGN4 / NL4 / NL4X / NLGN4X0.06
ALCAM / CD1660.19Notch-13.63
ASAM / CLMP / ACAM4.45Notch-20.44
Bcan / Brevican / BEHAB21.08NRP1 / Npn-1 / Neuropilin 1 / CD3041.75
Cathepsin B / APPS / CTSB / CPSB*1.16OPCML / OBCAM1.89
CathepsinC / DPPI / CathepsinJ / CTSC*3.66PDCD1 LG 1 / CD274 / B7-H1 / PDL117.98
CD118 / LIFR0.67PDCD1 LG 2 / PD-L24.87
CD11a / Integrin αLβ2 / LFA1 / INaLb21.02PDGF R beta3.54
CD11b / Integrin αMβ2 / MAC1 / INaMb22.42PECAM1 / CD311.14
CD4 / L3T4 / T413.36Plexin B3 / PLXNB35.6
CD48 / BCM1 / SLAMF2 / BLAST-131.7Plexin C1 / PLXNC1 / CD2320.08
CD58 / LFA314.83PRKCI / GST-PKC-γ80.74
CD81 (TAPA-1, TMSF)6.38PRL R3.7
CD84 / SLAMF516.8RAGE / AGER0.12
CDH12 / CAD126.81RGM-C / HFE2 / HJV0.16
CDH5 / 7B45.82ROBO25.05
CDH6 / KCAD0.56ROBO30.47
CDHE / CDH10.22SCFR / c-kit / CD117 / KIT0.03
CEACAM-5 / CEA / CD66e12.34SELP / P-Selectin / GMP-1400.25
CHL1 / CALL / L1-CAM20.72SIGIR R19.4
CNTFRA / CNTFR-alpha2.63SIGLEC145.6
CNTN4 / BIG-20.91SIGLEC3 / CD33 / CD33 antigen1.88
CNTN5 / NB-20.42SIGLEC51.29
DDR1 / CD167A4.14SIGLEC60.08
DNAM1 / CD226 antigen91.22SLAMF3 / CD229 / Ly96.22
EGFR / ErbB1 / HER-1 / ErbB0.62SN / Slglec-1 / CD1692.7
EIF4A*2.37SUMO1 / SMT3C / SMT3H3*0.33
Endoglin / CD10560.62TGF beta R III79.26
EPHA100.06TIE1 / Tie10.1
EPHA2 / Eck / Myk21.4TIE2 / TEK4.97
EPHB4 / Myk16.66TLR2 / CD2826.7
EPHB60.44TLR3 / CD2830.76
ERBB2 / HER2 / CD3400.78TLR4 / MD2 Complex4.04
ESAM0.96TNF sRII0.97
FGF R1 alpha(IIIb)15.7TNFR / TNF receptor4.26
FGF R1 alpha(IIIc)0.82TNFRI / CD120A / TNFRSF1A0.67
FGF R1 beta (IIIb)17.69TNFR SF10A / TRAIL R10.11
FGF R1 beta (IIIc)1.2TNFR SF10B / TRAIL R1 / DR52.21
FGF R3 beta0.28TNFR SF11A / RANK / ODFR5.52
FGF R3 C0.8TNFR SF11B / OPG / OCIF0.08
FGF R40.1TNFR SF13B / CD267 / TACI6.55
FLT-3 / FLK-2 / Stk-10.5TNFR SF13C / BAFFR23.68
Frizzled-1 / FzE1 / FZD16.44TNFR SF14 / HVEM8.9
GHR37.99TNFR SF17 / BCMA1.5
Glypican1 / GPC123.85TNFR SF19 / TROY / TRADE2.94
GPC20.85TNFR SF19L / RELT2.2
GPC3 / OCI5 / GTR-2 / MXR74.51TNFR SF21 / DR612.72
GPC50.26TNFR SF25 / DR35.52
GRP94*8.72TNFR SF4 / CD134 / OX401.29
HGF R / c-MET0.4TNFR SF5 / CD4026.49
HMGB1 / HMG1 / Amphoterin*0.05TNFR SF6 / FAS / APO-118.34
HSP90a / HSP 86 / HSP90AA1*17.6TNFR SF6B / DcR30.33
ICAM2 / CD1021.21TNFR SF7 / CD276.75
ICAM3 / CD500.17TNFR SF8 / CD300.98
ICOS / AILIM / CD278 / CRP-118.67TRAIL R4 / CD2641.66
IFN-gamma(γ) R2 / IFNGR23.07TRAIL / TNF SF10 / CD2534.53
IGF1 R / CD2210.66TrkB / NTRK22.97
IGSF4B / NECL1 / TSLL1 / CADM31.3TrkC / NTRK32.4
IL10 R alpha / IL10R1.29TROP2 / TACSTD21.23
IL12 R beta20.78TYRO348.39
IL13 R alpha230.53Ubiquitin*0.17
IL17R / IL17RA / CD21714VEGF R1 / FLT-10.14
IL17 R C / IL-17 RL / IL-17 Rhom14.1VEGF R2 / KDR / Flk-10.12
IL17 R D / SEF0.02VLA-3 / FRP-2 / CD49c / INa3b11.6
IL1 R2 / CD121b1.64VLA-5 / CD49e / INa5b11.47
IL1 R APL2 / IL1R917.82VRK1*5.34
IL23R0.08VSIG4 / CRIg / Z39IG1.91
IL2 R alpha / CD251.33XEDAR0.2
IL2 R beta / CD1227.84YES / GST-YES1*6.9
IL2 R gamma4.26BRF1*2.08
IL3 R alpha / CD123 / IL3R71.36CACNB3 / CACNLB3*0.7
IL5 R alpha / CD125 / IL5R22.83CD3470
IL6 R / CD1260.57CD63 / MLA1 / TSPAN308.81
IL6ST / gp130 / CD1300.88CD66b3.5
IL7 R alpha / CD1271.27CMPK1 / CMK / CMPK*1.84
IL9 sR / CD1295.15EEF1E1 / AIMP3 / P18*102
Integrin αVβ3 / INaVb317.57ErbB3 / Her34.81
Integrin αVβ6 / INaVb629.63ErbB4 / Her45.6
Integrin αVβ8 / INaVb86.84FAM107B*1.73
Interferon receptor4.67GSN-AS1*1.88
IR / Insulin R / CD2200.3LRP110.75
Legumain0.92PDPN / GP3685.74
Leptin R / OB-R / B2190.37Poly ubiquitin K63*0.4
Lin28*0.77PTPRC / CD4557.3
LRIG30.21TIGIT / VSIG9 / VSTM323.23
LRP620.82Ubiquitin D/FAT10*0.6


Target Protein (Other)Kd(nM)
E.coli Muts*0.13
HCV Core1.43
HCV E20.08
Mouse CD36 / SR-B30.17
Mouse EPHA1 / EPH / Esk52.43
Mouse / Leptin R / Lepr4.6
Mouse RAGE0.08
Mouse TLR1 / CD2811.87
Mouse TLR6 / CD28615.34
Mouse VSIG4 / CRIg / Z39IG0.88
Rat ROBO1 / DUTT18.79
Zebrafish Lin28*0.41


Can't find what you're looking for?

We offer a range of custom services for the design & synthesis of high quality Aptamers

AP/Co-AP Kits

Aptoprecipitation (AP)/Co-aptoprecipitation (Co-AP) kits are aptamer based protein precipitation kits for easy and quick protein precipitation, offering numerous advantages over other competing methods.


  • Complete kits: Aptamer provided as covalently conjugated to magnetic beads, so no troublesome conjugation step is necessary
  • Mild elution condition
  • Specificity: Aptamer recognizes the native form of target proteins, not the denatured form, unlike antibodies
  • Reusable aptamer beads
  • Storage and longer shelf life: stable even at high temperatures and for at least 1 year when stored at room temperature

Flow Cytometry Aptamers

AMSBIO offers dye-conjugated aptamers specifically designed to monitor protein expression by flow cytometry with high specificity. Flow cytometry facilitates quantitative, multi-parameter analysis of cell populations based on the expression of cell surface and/or intracellular molecules.

We supply a wide range of dye-conjugated monoclonal aptamers, which are compatible with all flow cytometers.


  • Range of dyes: Fluorescein isothiocyanate (FITC), cyanine (Cy3, Cy5) and others
  • Dye conjugations available at 5’ or 3’ end
  • High specificity: minimizes background caused by nonspecific binding


  • No secondary antibody or aptamer needed
  • No batch to batch variation
  • Storage stability- fluorescent dye-conjugated aptamers are stable for at least several months at room temperature

AptoPrep™ Cell Isolation Kit

AMSBIO offers the user-friendly AptoPrep™ Cell Isolation Kit for your cell isolation needs. Utilizing the specificity of aptamers to target cells, AptoPrep™ allows for the convenient isolation/elution of a particular cell from complex cell samples.


  • Fast, easy-to-use kit: Positive isolation in as little as 30 min. Released cells from bead are obtained in as little as 1 hour
  • Complete kit- biotinylated aptamer, streptavidin magnetic bead, and buffers are supplied for your convenience, increasing consistency and reliability
  • High specificity, yield, purity and viability
  • Mild and unique cell releasing technology allows you to isolate beads and aptamer-free cells. The isolated bead-free cells are ready for flow cytometry analysis and downstream molecular studies
  • No columns required- saves time and money, and your cells are not exposed to the stress of being passed through a dense column
  • Convenience in handling and longer shelf life

As well as biotinylated aptamer, we supply kits with FITC dye conjugated biotin aptamer, allowing you to perform the cell isolation and flow cytometry analysis simultaneously. Our bi-labeled aptamers have FITC at the 5’-end to monitor protein expression by flow cytometry and biotin at the 3’-end to separate target cells.