TABLE 3.
Comparison of aptamer‐based, nucleic acid‐based, serological‐based, and antigen‐based assays
| Parameter | Aptamer based assays | Nucleic acid‐based assays | Serological assays | Antigen‐based assay |
|---|---|---|---|---|
| Selection | In vivo | In vitro | In vitro | In vitro |
| Production | Chemical solid‐phase synthesis and machine learning techniques (Easy production) | A viable organism is not required | Immune response in animal origin | Easy production |
| Sample preparation | Not necessary | Pre‐analysis and additional detection after amplification is required | Pre‐analysis and preparation required | Not necessary |
| Cost | Cost‐effective | Expensive | Expensive | Cheaper |
| Specificity | Highest | Higher: Effective at low viral loads | Lower | Moderate: cannot detect low viral load |
| Sensitivity | Highest | Higher | High | Moderate |
| Target | Wide range of targets | Limited targets to nucleic acid | Limited to immunogenic targets | Viral proteins, N and S |
| Compatibility | Compatible with different diagnostic techniques | High susceptible to contamination | – | Less susceptible to contamination, compatible with |
| Rapidity | Very Rapid and real‐time detection | Moderately rapid | Slow (dependent on the amount and antibody type and availability) | Rapid |
| Size | Smaller | – | Larger | Small |
| Reusability | Reversible | – | Gets denatured and Irreversible | Irreversible |
| Complexity | Ease to use | Labor intensive and technicians are required | Labor intensive | Ease to use |
| Turnaround time | Shortest | Longer | Short | Shorter |
| Stability | Highly stable but sensitive to nucleases in serum and real samples | Low stability | Low stability (sensitive to conditions) | Impaired sensitivity and stability at elevated temperature |
| Labeling and modification | Simple | Dependent on labeling | – | – |
| Point‐of‐care | Applicable | Applicable | Applicable | Applicable |
| Equipment requirement | No need for expensive equipment and reagent | Expensive equipment and reagent required | Expensive equipment and reagent required | No need for expensive equipment and can be done by non‐expert |
| Shelf‐life | Longer | – | Shorter | Longer |
| Commercialization | Problematic | Available in the market | Available in the market | Available in the market |
| Standardization | Standard protocol not available except Pegaptanib aptamer | Standard and universal protocol available | – |