Will the TurboGFP still fluoresce in formaldehyde fixed cells or will I need to stain it with an anti-tGFP antibody?

TurboGFP does not stand the PFA fixation very well, the red fluorescent proteins are much more stable. However if you use short fixation time (10 minutes) the fluorescence will still remain detectable. If not, it will be necessary to use an antibody.