Jenway Genova Nano German - Manual (Page 17)

Nucleic acid concentration can also be estimated with the following calculations:
Conc (µg/ml) = (Abs@260nm x 62.9) - (Abs@280nm x 36.0)
Conc (µg/ml) = (Abs@260nm x 49.1) - (Abs@230nm x 3.48)
Referring to a blank value where no absorption should occur is commonly required. On the Genova Plus
the default reference wavelength is 320nm and the user can include the measured absorbance value in
all nucleic acid calculations. The default wavelength can be modified from 320nm if required.
3.3 SPECTROSCOPY MEASUREMENT
There are four main components of a spectrophotometer. These are a light source to emit a high and
constant amount of energy over the full wavelength range; a method for separating the light into
discreet wavelengths; a sample holder and a light detector.
The optical layout of the Genova Plus spectrophotometer is shown:
Figure 3.3.1 – Diagram of light path
The light from the pre-aligned xenon lamp is focused onto the grating, with 1200 lines per millimeter,
which separates the light into discrete wavelengths. The diffracted spectrum of light then passes through
a further slit and lens arrangement before passing through the sample in the sample chamber from left
to right. The light which is not absorbed by the sample is transmitted through a collecting lens and onto
the signal detector. The photo-diode detector used is mounted directly onto the detector PCB and the
output is used to calculate the % transmittance. The result is displayed either as % transmittance or
absorbance on the instrument display.
15