Microplate reader vs spectophotometer - (Oct/12/2011 )

To read absorbance, is it ok to use a microplate reader equipped with a spectrophotometer (in my case, BMG Labtech's Fluostar Omega) instead of a conventional spectrophotometer? I am using a protocol for protein quantification that calls for a spectrophotometer, but a microplate reader would be much more convenient for the number of samples I have.

Also, when reading absorbance in a microplate reader, does the volume of sample in the wells matter as long as I use the same amount per well?

yes, you can use a microplate reader.

as long as all of the samples and standards are the same volume they will be valid.

but, you may alter the useful range of detection.

In case your Microplate Reader fails, then you may use conventional spectrophotometer/nanodrop spectrophotometer however, it may increase your workload significantly.

Yes, you can use it, but be aware that OD measurements are very likely to be inconsistent across instruments, even after accounting for path length differences.