In our lab, we use the Bio Rad SmartSpec 3000 UV/Visible Spectrophotometer for measuring DNA concentrations, determining the purity of DNA samples (A260:A280) and for measuring the protein concentration of cell lysates. We typically use the Bradford assay for measuring protein concentration, but the SmartSpec can determine protein concentration for other assays as well, such as Lowry, BCA, etc., while storing up to 10 standard curves. The wavelength range is between 200 and 800 nm, with a wavelength accuracy of +/- 2 nm using a xenon flash lamp as a light source and a photodiode array as the detector. The xenon flash lamp is advantageous because it can produce both UV and visible light with less heat than other light sources and lasts longer because it only emits light during sample measurement. This spectrophotometer also utilizes a grating device (as opposed to a dispersion device), which increases accuracy and speed of measurement.
This spectrophotometer is very compact measuring only 33 cm (W), 26 cm (D), and 14 cm (H), and weighs a little less than 4 kg. It has an easy-to-use keypad, a built-in backlit LCD display, a cuvette compartment (accommodating 100 ul, 700ul, 1.5 ml, and 3.5 ml cuvettes) and a built-in thermal printer. A cuvette spring, which aligns the cuvette within the chamber, and a thermal paper roll come with the spectrophotometer, as does a convenient storage holder for holding additional samples to be measured.
As with most spectrophotometers, a self-diagnosis test is initiated upon powering up that checks the lamp and optics and notifies the user when the spectrophotometer is ready to use. Another convenient feature of this spectrophotometer is the ‘setup’ option, which maintains the current setting when the apparatus is not in use. The instrument is capable of automatically subtracting the background value from your sample readings while determining mean and standard deviation, which are huge pluses. Finally, printing options allow the user to print one reading, a selection of readings or all readings.
We found the Bio Rad SmartSpec 3000 Spectrophotometer to be very simple-to-use and compact in size, while requiring very little maintenance. Compared to the Hitachi model that I previously used, the Bio Rad SmartSpec delivers reliable data without the bulky size and maintenance requirements. I have not found any disadvantages with this product, to date. I highly recommend this product as a basic spectrophotometer for your laboratory.
Hee Chul Lee, Ph.D.
Post-doctoral scientist
Dept. of Biochemistry
NYU School of Medicine