Can GFP fluorescence be detected in cells that have been stained for beta-galactosidase?
We recommend looking for GFP fluorescence before staining for beta-galactosidase. This is because the beta-galactosidase staining process produces a very high autofluorescence that will interfere with detection of GFP fluorescence.
What are the recommended filter sets for detection of EmGFP, YFP, CFP, and BFP by fluorescence microscopy?
EmGFP, YFP, CFP, and BFP can be detected using standard FITC filter sets and settings. However, for optimal detection of the fluorescence signal, filter sets optimized for detection within the excitation and emission ranges for each fluorescent protein are recommended. The recommended filter sets are as follows:
EmGFP: Omega filter set XF100
YFP: Omega filter set XF1042
Chroma filter set 41028
CFP: Omega filter set XF114
Chroma filter set 31044
BFP: Omega filter set XF10
Chroma filter set 31021
For information on obtaining filter sets, please contact Omega Optical, Inc. (www.omegafilters.com) or Chroma Technology Corporation (www.chroma.com) directly.
What are the excitation and emission maxima for your fluorescent proteins (EmGFP, YFP, BFP, CFP, and Cycle 3 GFP)?
Excitation and emission maxima for our fluorescent proteins are as follows:
- EmGFP: Excitation: 487 nm; Emission: 509 nm
- YFP: Excitation: 514 nm; Emission: 527 nm
- BFP: Excitation: 308-383 nm; Emission: 440-447 nm
- CFP: Excitation: 452 nm; Emission: 505 nm
- Cycle 3 GFP: Primary excitation: 395 nm; Secondary Excitation: 478 nm; Emission: 507 nm
Are the fluorescent proteins you offer (EmGFP, YFP, CFP, BFP, and Cycle 3 GFP) humanized?
Yes, all of the fluorescent proteins offered by us (EmGFP, YFP, CFP, BFP, and Cycle 3 GFP) have been humanized for optimal mammalian expression.
How does Cycle 3 GFP compare with EmGFP and EGFP?
EmGFP is the next-generation variant of EGFP, and it has been further optimized for mammalian expression. Both EmGFP and EGFP can be visualized using the same filter sets (FITC) and settings. When used with the recommended filter sets and settings, Cycle 3 GFP is as bright as EGFP or EmGFP. However, when used with FITC filter sets and settings, Cycle 3 GFP is not as bright as EmGFP or EGFP.
- Excitation/emission maxima for EGFP: 488 nm/507-509 nm
- Excitation/emission maxima for EmGFP: 487 nm/509 nm
- Excitation/emission maxima for Cycle 3 GFP: 395 nm (primary) and 478 nm (secondary)/507 nm