Section 5- Nucleic Acids
Sample Type:
used to select the (color-keyed) type of nucleic acid
being measured. The user can select ‘DNA-50’ for dsDNA, ‘RNA-40’
for RNA, ‘ssDNA-33’ for single-stranded DNA, or ‘Other’ for other
nucleic acids. The default is DNA-50. If ‘Other’ is selected, the user
can select an analysis constant between15-150. When navigating
amongst the three general sample types within the Nucleic Acids
module, the last constant value entered within the ‘Constant’ sample
type will be retained. See the “Concentration Calculation (Beer’s
Law)” Appendix for more details on this calculation.
λ
and
Abs:
the user selected wavelength and corresponding
absorbance. The wavelength can be selected by moving the cursor
or using the up/down arrows to the right of the wavelength box. Note:
The user-selected wavelength and absorbance are not utilized in any
calculations.
A260 10 mm path:
absorbance of the sample at 260 nm represented
as if measured with a conventional 10 mm path. Note: This is 10X the
absorbance actually measured using the 1 mm path length and 50X
the absorbance actually measured using the 0.2 mm path length.
A280 10 mm path:
sample absorbance at 280 nm represented as if
measured with a conventional 10 mm path. Note: This is 10X the
absorbance actually measured using the 1 mm path length and 50X
the absorbance actually measured using the 0.2 mm path length.
260/280:
ratio of sample absorbance at 260 and 280 nm. The ratio of
absorbance at 260 and 280 nm is used to assess the purity of DNA
and RNA. A ratio of ~1.8 is generally accepted as “pure” for DNA; a
ratio of ~2.0 is generally accepted as “pure” for RNA. If the ratio is
5-2
