I am a 3rd timer postdoctoral fellow with some experience in molecular biology and biochemistry, but major skills in Zoology and Natural History. I am studying some natural extracts, and isolating compounds.

Some biological samples come in limited amounts (e.g. invertebrate haemolymph), hampering analytical methods that rely on larger amounts. For instance, establishing UV-Vis spectra of extracts is a usual non-destructive method for approaching unknown samples and estimating general parameters, done with a spectrophotometer.

The microvolume-scaled spectrophotometer system popularly known as 'Nanodrop' has been around labs since almost two decades now. Its use has been usually limited to fast purity & concentration estimations for DNA & RNA in molecular biology labs.

I am considering using the nanodrop to estimate parameter of other biological and chemical samples. The manual says most commonly used solvents are compatible with the system. I have however yet found no-one else who has tried using Nanodrop for different applications.

Please, anyone here who has experimented using a Nanodrop system with other biological samples and extracts could comment on the experience?


The Nanodrop is a generic UV-visible spectrophotometer. According to the manufacturer, the latest model can measure absorbance from 190 to 850 nm. Its dynamic range is also very good: from about 0.1 to about 60 in absorbance. Therefore, as long as you don't use an incompatible solvent, you can measure anything that absorbs in this wavelength range. I use it very often for purified proteins. It also works well for turbid suspensions (like bacterial cultures; reading optical density at 600 nm gives an idea of turbidity).

It is easy to use, and of course the low volume requirement is a big advantage. One drawback is that it won't let you fine tune certain parameters like a "real" spectrophotometer would allow (bandwidth, gain, etc.). But you can definitely get decent spectra for characterization of mixtures and concentration estimation of pure samples.

  • $\begingroup$ 'you can measure anything that absorbs in this wavelength range' -- Yes, I have been trying out for the first time recently. But have you officially done it? My peers seemed revolted as they state a nanodrop should be used only for DNA/ RNA/ protein standards. They sounded so dogmatic. $\endgroup$ – Scientist Feb 11 '18 at 7:05
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    $\begingroup$ Yes, I have measured absorption of fluorescent dyes that is nowhere near absorption wavelength of proteins or nucleic acids. Using a Nanodrop only for proteins and nucleic acids seems like a lab policy (in my opinion, too strict and not justified), but it is definitely not a technical limitation of the instrument. $\endgroup$ – Guillaume Feb 12 '18 at 15:51

I used the Nanodrop for the measurement of the absorbance at 600 nm of bacterial cultures, as well as nucleic acid preparations. However, I switched to using another spectrophotometer (Spetrophotometer, Ultrospec 2100 pro, UV/Visible Spectrophotometer, Amersham Biosciences) for my bacterial cultures because I trust it more due to using a cuvette containing 1 ml of bacteria instead of just 1 microlitre of culture.

  • $\begingroup$ In fact some nanodrop models do have a special pedestal for measuring OD600 of microbial growth. I ought to have mentioned that in my brief intro for the question. My main issue is, as soon as I mentioned to peers I'd be using nanodrop with other biological samples they got revolted, stating 'a nanodrop should be used only for DNA/ RNA/ protein standards'. I was wondering why they sounded so dogmatic about it, and how readers would receive if I employed it otherwise. $\endgroup$ – Scientist Feb 11 '18 at 7:09
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    $\begingroup$ Maybe some people measure their sample and retrieve afterwards and you are contaminating the system. They might be concerned that their sample gets contaminated? $\endgroup$ – charlesdarwin Feb 11 '18 at 13:07
  • $\begingroup$ Perhaps. Nanodrop is naturally unstable, and people may blame anything for a weird result. But if samples are soluble in compatible solvents, I see no logical point, and they really declared they believe it is designed solely for nucleotide analysis (which is not what it says in the manual). $\endgroup$ – Scientist Feb 11 '18 at 14:36

After completing my tests, I have decided to come back to answer my own question.

A Nanodrop machine has served my purpose quite efficiently, as far as I can judge. I used have used it to evaluate the degree of purity of a natural alkaloid extract from insects, using synthetic alkaloid analogues as controls. See our published paper discussing the method here, along with raw data.

We have noticed no alterations nor cross contaminations to colleagues' DNA/RNA samples running in parallel, highlighting on the fact that I properly cleaned the equipment between use.

Therefore, yes: I recommend using the Nanodrop as a cheap & quick method to scan biological samples, provided chemicals and solvents used in cleaning the pedestal are compatible with the manual.

Hope this discussion help others dare!

  • $\begingroup$ @WYSIWYG I reckon we did what you describe, no? On using synthetic compounds as standards and doing a wavelength scan? $\endgroup$ – Scientist Jun 24 '19 at 13:29
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    $\begingroup$ Sorry. I did not see it. Also, if you use the "UV-Vis" mode (I have nanodrop 1000), you can choose two wavelengths (in other assays, the wavelengths are fixed). I assume you used that. $\endgroup$ – WYSIWYG Jun 24 '19 at 14:44

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