Fluorescent Sample with Cuvette but not with Plate -- Why?

[RooneyChemistry]

TL;DR Summary

Fluorescent Sample with Cuvette but not with Plate

I am doing an assay where the formed compound is fluorescent when I use a cuvette in a fluorometer, but not when I put the same sample into the well of a 96 well plate. Why is this?

The fluorometer reads from the top and the plates I am using are 96 well plates, black, flat-bottomed well, opaque bottom, fluotrac from Greiner.

Exc. 468 nm, Em. 572 nm.

 

[DaveE]

Are you sure it's not the cuvette that's fluorescent?
https://www.researchgate.net/figure...and-fused-silica-coverslips-as_fig1_224946514

 

[chemisttree]

What kind of fluorometer are you using? Exc from above or below?

 

[HAYAO]

Yeah we lack information here. What is the cuvette made out of? Fused silica? Borosilicate glass? Quartz? How about the well plate? I am also unsure what fluorometer excites from above. Most of them are sideways, where detection are perpendicular to the excitation path.

 

[chemisttree]

A 96 well fluoro reader couldn’t excite from the side, could it?

 

[DaveE]

A 96 well fluoro reader couldn’t excite from the side, could it?

Maybe with tomography, LOL. A most expensive method.

 

[CheesyG]

Probably the sensitivity and different background noise of each instruments. Plate readers used in bio-assays are generally much less sensitive than traditional cuvette fluorometers. You could also get some background noise if your detector is not at a right angle from the light source.