DNA is colorless, so if we want to see it, we need to use staining techniques. Since the maturity of PCR technology, DNA staining methods have been widely developed, and we want to use the cheapest, easiest and safest method for the most sensitive and efficient staining. Let’s talk about several common fluorescent dyes.
| Laser | Name | Excitation wavelength (nm) |
Emission peak (nm) |
Relative Strength (1-5) |
Optical Filter |
| Violet Laser | eFluor® 450 | 405 | 450 | 2 | 450/50 |
| eFluor® 605NC | 405 | 605 | 2 | 605/40 | |
| eVolve™655 | 405 | 655 | 3 | 660/40 | |
| Blue Laser | FITC (Fluorescein Isothiocyanate) | 488 | 518 | 3 | 530/30 |
| Alexa Fluor® 488 | 488 | 519 | 3 | 530/30 | |
| R-PE (R-Phycoerythrin) | 488 | 578 | 5 | 575/26 | |
| PE-eFluor® 610 | 488 | 607 | 3 to 4 | 610/20 | |
| PE-Cyanine 5 | 488 | 667 | 4 | 670/14 | |
| PE-Cyanine 5.5 | 488 | 695 | 3 to 4 | 695/40 | |
| PerCP-Cyanine 5.5 | 488 | 695 | 3 | 695/40 | |
| PerCP-eFluor® 710 | 488 | 710 | 4 | 710/50 | |
| PE-Cyanine 7 | 488 | 785 | 3 | 780/60 | |
| 7-AAD | 488 | 647 | -- | 670/14 | |
| Propidium Iodide (PI) | 488 | 617 | -- | 575/26 | |
| Green Laser | Alexa Fluor® 532 | 532 | 561 | 3 | 560/14 |
| R-PE (R-Phycoerythrin) | 532 - 561 | 578 | 5 | 575/26 | |
| PE-eFluor® 610 | 532 - 561 | 607 | 3 to 4 | 610/20 | |
| PE-Cyanine 5 | 532 - 561 | 667 | 4 | 670/14 | |
| PE-Cyanine 5.5 | 532 - 561 | 695 | 3 to 4 | 695/40 | |
| PE-Cyanine 7 | 532 - 561 | 785 | 3 | 780/60 | |
| Red Laser | APDye Fluor 647 | 633 | 660 | 4 | 660/20 |
| eFluor® 660 | 633 | 660 | 4 | 660/20 | |
| Alexa Fluor® 647 | 633 | 668 | 4 | 660/20 | |
| Cy5 | 633 | 670 | 3 | 660/20 | |
| Alexa Fluor® 700 | 633 | 723 | 2 | 685 LP and 710/20 | |
| APC-eFluor® 780 | 633 | 780 | 2 | 780/60 |
