Please note that the NanoDrop 1000 is no longer available. It has been replaced by the NanoDrop 2000
Review of NanoDrop 1000:
A spectrophotometer is an instrument that measures that intensity of color in a linear range. Spectrophotometry is a study that involves measurements of light intensity in the visible, near ultra violet and near infrared ranges. Spectrophotometers are used extensively in laboratories of physics, chemistry, biochemistry and molecular biology to name a few. Often, measurements of the concentrations of various compounds or biological materials are done by first performing a color producing reaction and subsequently measuring the color intensity using a spectrophotometer. These instruments are used widely for measuring the concentration of proteins and nucleic acids. Generally, protein concentration measurements are done in the visible range and therefore involve a color producing reaction such as Bradford or Lowry reaction prior to measurement at the appropriate wavelength. Measurement of nucleic acids is usually done at 260/280 nm in the UV range and so does not require an initial color reaction.
Spectrophotometry is a very old technique and several generations of instruments have evolved over time. Most instruments, however, make use of either glass (for color) or quartz (for UV) cuvettes for measurement. This requires a sample size ranging from 100 to 1000 ul, resulting in loss of sometimes very precious sample. ThermoScientific NanoDrop has come up with the NanoDrop 1000 spectrophotometer whose most attractive feature is that it needs just 1ul of sample for accurate measurement.
The NanoDrop 1000 has several features that are unique and very useful to researchers. Besides using very small quantities of sample for measurement, the size of the instrument itself is attractive. Compared to the conventional spectrophotometers that are very large and space consuming, the NanoDrop 1000 is extremely small, about the size of a Kleenex box. In most instruments, where glass or quartz cuvettes are used, cleaning of the cuvette between measurements involves washing and wiping. This could lead to potential sample contamination/ dilution. In the NanoDrop protocol, since very small quantities of sample are involved, cleaning just requires wiping the sample loading surface clean with a KimWipe. Another useful feature of the NanoDrop 1000 is that it comes with its own software which is very user friendly and useful. Concentrations of various samples are automatically computed and the purity can also be visualized through the graphs that are automatically generated. These data can either be saved to file or printed for future reference.
We have had the NanoDrop 1000 in our laboratory for about three years. Although the manual for this instrument suggests several applications, we have only used this instrument for measurement of the concentration and purity of DNA and RNA, and for this application, we have found that the performance of the instrument is excellent. Since protein quantification requires using a color-generation method, such as the Bradford assay, prior to measurement, the same amount of original protein sample must be sacrificed to the color-generating assay, regardless of the spectrophotometer that is ultimately used for quantification. For this reason, we have found that the NanoDrop 1000 doesn't provide any advantage when it comes to protein measurement.
In summary, the NanoDrop 1000 is an excellent instrument for measurement of nucleic acid concentrations.