Table 1.
A comparison of four of the most common DNA microarray formats
|
|
Contact printing |
Inkjet synthesis |
Affymetrix |
NimbleGen |
|---|---|---|---|---|
| Arraying method | Mechanical deposition | Phosphoramitide synthesis, piezoelectric printing | In situ DNA synthesis (photolithography) | In situ DNA synthesis (maskless photolithography) |
| DNA size limit | None | ∼60 nt | 25 nt | ∼100 nt |
| Feature type | PCR products, oligomers | Oligomers | Oligomers | Oligomers |
| Features/slide | ≤40 K | ≤40 K | 60 K–6.2 M | 200–800 K |
| Array design | Flexible | Flexible | Fixed | Flexible |
| Fabrication cost | High (DNA preparation) | Moderate | High | Low |
| Array cost
|
Low
|
Moderate
|
Moderate
|
Moderate
|
-
While contact-printed arrays allow for unlimited customization, the initial production cost can be prohibitive compared with the relatively affordable but fixed-array designs commercially available. Maskless photolithographic arrays represent a trade-off between these platforms, allowing customized design while maintaining very high feature density.
