Use of Antibodies vs Aptamers as Recognition Element

Both antibodies and aptamers bind to a wide range of biological targets, from small molecules to proteins to whole cells, with a high degree of specificity and selectivity.


Antibodies have a richly researched history in biochemical detection. They are produced by an animal inoculated with the target (polyclonal antibodies) or a specific cell line derived from a target-immunized animal (monoclonal antibodies).

Aptamers are a more recent addition to the world of biosensors. First discovered in 1990, aptamers are short oligonucleotides selected against a target molecule by a process called SELEX: systematic evolution of ligands by exponential enrichment, where molecules with the highest affinity are selected through rounds of mutation and selection.

Both antibodies and aptamers are interesting candidates when developing a diagnostic assay:

Comparison of Detection Assay Advantages/Disadvantages  



Applicability in diagnostics well researched and documented

Burgeoning in biochemical diagnostics field 

Produced relatively quickly

Long and labour-intensive SELEX process

Target molecules that do not generate immune response must be conjugated to carrier (e.g., BSA)

Immune response not required

Costly to produce each batch

Cost-effective production once sequence in known

20 amino acids with a wide range of functionalities/interactions

Only 4 natural nucleotide bases with similar functionalities/interactions

Variability between production sources/batches

Highly reproducible manufacturing

Highly sensitive to storage conditions/freeze thaw cycles

Much more stable, no freeze thaw degradation

Specific buffers required for stability

Stable stored in water

Easily conjugated to enzymes, fluorescent molecules, etc. for detection

Location-specific 5’ or 3’ functionalization possible (e.g., thiol for gold conjugation, biotin, amine, fluorescent molecule)

Antibodies for novel targets typically not commercially available

Easily produced the moment sequence is available in scientific literature


Overall, antibodies and aptamers have unique advantages and disadvantages. Depending on the requirements of the assay, one recognition element may be better suited. It is also possible to use both antibodies and aptamers within the same assay!

Contact us for more information regarding which recognition element to use for your assay development.