Wealtec SpectroArt 200 Installation And Operation Manual - D. Quick Guide To Assays
SpectroArt 200 V1.0
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D. Quick Guide to Assays
D-1. DNA/RNA
This function enables measurements of double-stranded DNA, single stranded DNA and RNA.
With the help of a conversion factor, that is, the concentration of nucleic acid at 1.00 absorbance
units at 260 nm, and the dilution factor, the concentration of DNA or RNA in your sample can be
determined. The conversion factor differs according to the type of nucleic acid that is measured.
The default conversion factors used by SpectroArt 200 are 50.0 µg/ml, 37µg/ml or 40 µg/ml for
double-stranded DNA, single-stranded DNA and RNA respectively. Hence, the concentration of
DNA or RNA is calculated as follows;
Conc = A260 nm* conversion factor * dilution factor
Or, if 320 nm correction is enabled;
Conc = (A260 nm – A320 nm) * conversion factor * dilution factor
SpectroArt 200 measures the purity of DNA or RNA in a sample by dividing the DNA or RNA
absorbance values by the absorbance of protein at 280. If 320 nm correction is enabled, the
readings from this wavelength are subtracted from both DNA/RNA absorbance-values and
protein absorbance-values. With SpectroArt 200 you can also measure other forms of nucleic
acids at your customised wavelength with your customised conversion factor.
To measure DNA or RNA, enter the setup menu to choose dsDNA, ssDNA or RNA under “sample
target”. Choose whether to enable 320 nm-correction or not. Exit setup and read the blank.
When you touch “Sample”, you are asked to enter the dilution factor using the number pad.
Press “Enter” and read the sample.
D-2. Protein
SpectroArt 200 has four different programmed assays for protein concentration measurements.
Three of these (Bradford 595 nm, Lowry 750 nm and BCA 562 nm) are common colorimetric
assays that measure changes in absorption at a fixed wavelength in the visible light region.
Protein can also be measured with SpectroArt 200 within the UV-light range at 280 nm. This
assay can be used when measuring protein in an environment such as a crude cell extract where
nucleic acids are present. It is also possible to choose a custom wavelength anywhere in the
wavelength range for other assays. To choose one of the programmed assays, enter the protein
setup menu. The default setting is Bradford 595 nm. Touch the “method”-button in the setup