review of the NanoDrop 2000c

May 11, 2009 at 12:04 pm | | hardware

Our lab recently bought a NanoDrop 2000c spectrometer. It sure is cute:

nanodrop

Just look at it next to our old Perkin-Elmer Lambda-19 spectrometer:

nanodrop_lambda19

(Although, that’s not really a fair comparison, because the Lambda-19 is a real spectrometer, with high sensitivity and resolution.)

The ND 2000c has a small pedestal with a fiber at the base; onto said pedestal, a research may place 2-5 uL (or even less!) solution and the dang machine measures the absorbance! The pedestal has a mechanism to move up and down in order to change the pathlength (the solution forms a small column between the pedestal and anther fiber above it). Very cool. The detector is a linear CCD array, so no scanning: hit go and a second later a spectrum pops up on the screen.

Of course, the sensitivity of the detector is less than that of our old real spectrometer, and the resolution is set by the CCD array—I don’t think the grating or most other parts inside move. But, with a high enough concentration, you can get quick-and-dirty spectra that actually look pretty good.

The ND 2000c also has an extra measuring mode, because it has a cuvette holder. Click a few buttons and the spectrometer measures the solution in a standard 1-cm cuvette (or, of course, small-volume or short-pathlength cuvettes, but why would you when you have the cool pedestal mode?). The cuvette holder also has a stirplate and heater, so you can measure biological samples or run reactions. Same issue with sensitivity and resolution, but I was able to get some usable spectra of a chromophore by using high enough concentrations and tweaking some settings:

nd2000c-lownd2000c-low-zoomnd2000c-all

Ignore the changes in the shape of the peak as the concentration increases (that is from different ratios of ethanol and water in the mixture). The higher-concentration samples produce spectra that are publishable; low-concentration samples are probably too noisy and low-resolution to pass as publishable spectra. Nevertheless, the repeatability even at low concentration is acceptable.

My biggest complaint so far is the software. Of course, this may be because I am learning a new interface after five years of using the Lambda-19, but I find the ND 2000c software confusing, limiting, and sometimes buggy.

For example, a user cannot directly change the integration time in order to better measure low-concentration samples. Instead, the software automatically sets the integration time for each run based on the amount of light incident on the detector. This is probably a good thing, because it prevents a user from inadvertently overexposing and damaging the CCD; but it’s still kind of annoying. Fortunately, the tech reps helped me by explaining how to set a wavelength range just around the peak of interest (i.e. not UV peaks), so the integration time resets to best measure that peak. (If I had not done that in the spectra above, they would have looked really crappy!)

The customer and tech service has been awesome so far. When I was thinking about buying the ND 2000c, the sales rep sent me sample spectra and answers a lot of my questions. Now that we have the spectrometer, I’ve communicated with two of the tech reps on the phone and via email and they’ve helped me with some the tricks and tips of using the software.

7 Comments »

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  1. Ah, but does it brown the toast on both sides?

    Comment by jordan — May 12, 2009 #

  2. Nice toy. It must be expansive though. I have been looking for a Tek 7J20 RSS, a plug-in spectrometer for the Tek 7000 series scopes. It was developed in a group I worked in at Tek in the late 70s. I got a grating from one but now I think I could afford the whole instrument.

    Comment by Eric Juve — May 12, 2009 #

  3. congrats sam! The next thing you guys should buy is a bioanalyzer, my current favorite piece of lab equipment

    Comment by lsc — May 19, 2009 #

  4. Hi, Eric.

    Do you by any chance have a manual for the Tektronix 7J20? I’ve been offered one, but I’d like to know what’s inside. It may not be working, so I’d like some background on fixing it or modifying it perhaps to work as a non-scanning spectrometer / spectrograph.

    Thanks in advance,

    Pete

    Comment by Pete Albrecht — June 15, 2009 #

  5. I happen to have a J20 RSS (Rapid Scan Spectrometer) with the 7J20 controller, which plugs into a TEK 7000 series scope mainframe. The instrument is shown in the 1974 catalog only, and at that time cost US $10,000.-, much more than the most expensive 7000 series mainframe (TEK 7844) at that time.
    I also have a J20/7J20 service manual, which has detailed specifications, circuit description, maintenance and calibration information, as well as all schematics for the J20 and 7J20. Only the the section with operating instructions is quite short. Detailed op info is available in a separate manual, but I don’t have a copy of this one.
    Regards
    Yngve

    Comment by Yngve von Spalden — June 22, 2009 #

  6. Hi Guys,

    I have less than a 2 years old Nanodrop 2000. It had a problem of communication bewteen the computer. A swop between a good and a bad ND 2000 reveals that the spectrometer is defective. Can some one share with me what is the estimated cost of replacing a spectrometer in a ND 2000 Nanodrop.

    Thank you
    Patrick

    Comment by patrick Ng — August 22, 2010 #

  7. I think you should contact NanoDrop (or Ocean Optics, who makes the spectrometer, I believe).

    Comment by sam — August 23, 2010 #

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