On Dec 4th last year I asked for recommendations for a UV
spectrophotometer to determine the concentration of protein/ [RD]NA
samples.
I received an enormous amount of answer emails, both to the board and
privately and I am trying to summarise them as good as possible.
We finally decided for a GeneQuant 1300 from GE Healthcare
(http://www4.gelifesciences.com/aptrix/upp01077.nsf/Content/spectrophotometry_site~spectro_meter~spectro_mol_bio~genequant_pro?OpenDocument&parentid=80211498&moduleid=167189)
for the following reasons
- wide wavelength range (190 - 1100 nm, 5nm bandwidth)
- small display to show the spectrum
- built-in (thermo) printer
- no need for a controlling PC
- price about 4,000 Euro
- small enough to be carried between labs
- It can play Tetris (;->)
Following is an attempted summary of all the replies
- most people (the vast majority, actually) advocated the Nanodrop 1000
(http://www.nanodrop.com/),
which costs about 10,000 Euro (I believe).
The main argument was that you only need 1ul and that it was fast.
Several people pointed out that they found the nanodrop to be
inaccurate, especially over time and repeating a measuremant would
produce a considerable variation
Others liked that you could re-use the sample for it was measured
undiluted due to the short path length
Personally I did not like the need of a controlling PC to record the
measurement
- The Biorad BioPhotometer Plus was in the same price range as the
GeneQuant (4,000 Euro), but only measures at 9 fixed wavelengths and
does not have a display to show the measured spectrum.
- The Biorad Smartspec 3000 has got a wavelength range of 200-800nm, and
only a 2 line matrix display. I don't know the price
- The Beckman Coulter DU-730
(http://www.beckman.com/products/instrument/analytical/uvvis/duseries700_inst_dcr.asp)
was recommended by one person. It seems to
have similar features (both technically and in measure) as the GeneQuant
although with a slightliy improved bandwidth (3nm). It includes a
display that show the spectrum. I don't know how much it costs.
- The Cary 50 (Varian,
http://www.varianinc.com/cgi-bin/nav?products/spectr/uv/cary50/cary50&cid=HFIH)
was too big for our purposes.
- USB2000+ (Ocean Optics,
http://www.oceanoptics.com/products/usb2000+.asp) is a low-cost solution
(< 3000USD) but requires a PC for control to spoil the prive. It also
covers 200nm-1100nm. The Ocean Optics USB4000 was also recommended once.
- The Shimadzu UV2450 (successor of UV2401)
(http://www.shimadzu.com/products/lab/spectro/oh80jt0000001k16.html)
was again a little too big for our lab since we were looking for a
protable machine.
I hope, but don't claim this information is complete.
I am grateful to everybody who answered and hope not to disappoint the
about 90% voters for the Nanodrop system for choosing a different machine.
Tim
--
Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen
GPG Key ID = A46BEE1A
