I am working at department of biophysics, Panjab University, Chandigarh, India as a Senior Research Fellow. I often use the UV spectrophotometer from Shimadzu for various biochemical assays which require detection of optical densities at wavelengths ranging from ultraviolet to visible range. As part of my work, I have to estimate enzyme activities of antioxidant enzymes, cancer marker enzymes, and estimate protein concentrations of large numbers of samples. Biochemical enzyme estimations involve the estimation of their activities on the basis of a change in optical density with respect to time. This requires an efficient analyzer which is able to record multiple readings and is able to work across different wavelength ranges. This requirement is fulfilled by Shimadzu's UV-1800 spectrophotometer. I rated this instrument with respect to sensitivity and specificity. I found it to be excellent in performance, and allows the user to work on a large number of samples (250).
The spectrophotometer is a compact double beam system which offers the high resolution of 1 nm. It can be used both as a stand alone instrument and as a PC controlled instrument. It is also equipped with USB memory connectivity which allows analysis of data on the PC using its ‘UVprobe’ software. Further, spectra data and time course curves can be displayed and saved with commercial spread sheet software and can be printed subsequently. It has two operating modes, namely photometric and spectrum mode. The photometric mode measures absorbance or transmittance at a single or multiple wavelengths (up to 8 wavelengths). In multi wavelength mode, calculations like the difference between two measurements or the ratio of two measurements can be easily performed. Further, spectrum mode gives sample spectra using wavelength scanning. Data processing operations like enlargement or reduction of the spectra, peak detection, area calculation are also possible.
I found the Shimadzu UV-1800 spectrophotometer fast, easily operable, compact, sensitive and user-friendly. It also provides us with an easy-to-use tool for comparative studies of different samples using its graphical UV/Visible spectrums. Its built-in software allows us to save various programs designed for different enzymatic estimations. The drawback of the spectrophotometer is its cost. Secondly, the software on the connected PC is bit complex; you have to look-in into lot of parameters before starting the application. Also, direct printing from the onboard USB of the instrument is not easy. Finally, it requires 15- 20 minutes for initialization of the instrument so you have to wait before you start taking readings.
I recommend the Shimadzu UV/Visible spectrophotometer for its speed, compactness, technology, sensitivity, and large sample size analyses.