| Probe . | Spectral properties . | Usage notes . | Example references . |
|---|---|---|---|
| Monobromobimane | λex = 394 nm | Very small size compared with other probes allows labeling of less accessible locations with lower risk of structural perturbation. Near-UV excitation may cause aberrant photodamage. | Islas and Zagotta, 2006; Taraska et al., 2009 |
| λem = 490 nm | |||
| DPTA-Tb3+ | λex = 328 nm | Terbium chelate used in LRET studies. Reduced orientation-dependence of energy transfer makes it a more reliable reporter for distance changes than conventional fluorophores. Requires laser excitation in UV range. | Cha et al., 1999; Posson et al., 2005 |
| λem = 492 or 546 nm | |||
| Fluorescein | λex = 494 nm | Bright, environmentally sensitive fluorescent probe but has pH sensitivity in the physiological range (pKa = 6.4) and is prone to photobleaching. | Cha and Bezanilla, 1997; Dempski et al., 2006 |
| λem = 512 nm | |||
| Alexa Fluor 488 C5 | λex = 493 nm | Bright fluorescent probe with low pH sensitivity in the physiological range. Lower environmental sensitivity of emission makes it less sensitive to conformational changes in absence of added quenchers. | Zheng and Zagotta, 2000; Bruening-Wright et al., 2007 |
| λem = 516 nm | |||
| Oregon Green | λex = 501 nm | Derivative of fluorescein with reduced pH sensitivity due to lower pKa (4.6) and lower rate of photobleaching. Emission is highly sensitive to calcium concentrations. | Cha and Bezanilla, 1997 |
| λem = 526 nm | |||
| PyMPO | λex = 415 nm | Environmentally sensitive probe whose linear shape makes it less bulky than alternatives such as fluorescein or tetramethyl rhodamine. Extended shape means probe reaches far from point of labeling. | Savalli et al., 2006; Vaid et al., 2008 |
| λem = 570 nm | |||
| Tetramethyl rhodamine | λex = 548 nm | Most commonly used probe with high environmental sensitivity and good photostability. | Mannuzzu et al., 1996; Cha and Bezanilla, 1997 |
| λem = 576 nm |
| Probe . | Spectral properties . | Usage notes . | Example references . |
|---|---|---|---|
| Monobromobimane | λex = 394 nm | Very small size compared with other probes allows labeling of less accessible locations with lower risk of structural perturbation. Near-UV excitation may cause aberrant photodamage. | Islas and Zagotta, 2006; Taraska et al., 2009 |
| λem = 490 nm | |||
| DPTA-Tb3+ | λex = 328 nm | Terbium chelate used in LRET studies. Reduced orientation-dependence of energy transfer makes it a more reliable reporter for distance changes than conventional fluorophores. Requires laser excitation in UV range. | Cha et al., 1999; Posson et al., 2005 |
| λem = 492 or 546 nm | |||
| Fluorescein | λex = 494 nm | Bright, environmentally sensitive fluorescent probe but has pH sensitivity in the physiological range (pKa = 6.4) and is prone to photobleaching. | Cha and Bezanilla, 1997; Dempski et al., 2006 |
| λem = 512 nm | |||
| Alexa Fluor 488 C5 | λex = 493 nm | Bright fluorescent probe with low pH sensitivity in the physiological range. Lower environmental sensitivity of emission makes it less sensitive to conformational changes in absence of added quenchers. | Zheng and Zagotta, 2000; Bruening-Wright et al., 2007 |
| λem = 516 nm | |||
| Oregon Green | λex = 501 nm | Derivative of fluorescein with reduced pH sensitivity due to lower pKa (4.6) and lower rate of photobleaching. Emission is highly sensitive to calcium concentrations. | Cha and Bezanilla, 1997 |
| λem = 526 nm | |||
| PyMPO | λex = 415 nm | Environmentally sensitive probe whose linear shape makes it less bulky than alternatives such as fluorescein or tetramethyl rhodamine. Extended shape means probe reaches far from point of labeling. | Savalli et al., 2006; Vaid et al., 2008 |
| λem = 570 nm | |||
| Tetramethyl rhodamine | λex = 548 nm | Most commonly used probe with high environmental sensitivity and good photostability. | Mannuzzu et al., 1996; Cha and Bezanilla, 1997 |
| λem = 576 nm |
DPTA, diethylenetriaminepentaacetic acid; PyMPO, 1-[3-(succinimidyloxycarbonyl)benzyl]-4-[5-(4-methoxyphenyl)-2-oxazolyl]pyridinium bromide.