If using a BioTek® fluorescent reader, can I keep the machine on all day?

Unfortunately, no, Technoclone and BioTek® recommend running only 2 consecutive runs and to switch the reader off for ~2-3 hours before starting the next run. The intensity of the lamp begins to diminish after too long. In addition, the bulb should be changed once a year (lifespan is ~500 hours anytime the instrument is on).