Manual

2. Background compensation. When using the DNA/RNA assay, you can choose to have
SmartSpec 3000 automatically subtract background absorbance readings collected at 320
nm from the A260 and A280 measurements. If the background subtraction option is
invoked, then the A320 is subtracted from the A260 and A280 readings before these
measurements are displayed and before they are used in the calculation of nucleic acid
concentration. The default condition is to subtract the A320 background. You can toggle
background subtraction on and off by pressing Select.
3. Default type of Nucleic Acid. SmartSpec 3000 can convert absorbance reading of nucleic
acid solutions into concentration. The conversion factor is determined by the type of
nucleic acid being measured. You can select the default type of nucleic acid in Setup, so
that when you press DNA/RNA, this type of nucleic acid will be shown first on the
display. You can choose another type of nucleic acid at any time by pressing Select. The
choices are double-stranded DNA (dsDNA), single-stranded DNA (ssDNA), RNA, DNA
oligo and RNA oligo. The factory default choice is dsDNA.
4. Default method to determine oligo molar extinction coefficient and molecular weight.
SmartSpec 3000 uses the molecular weight and molar extinction coefficients of
oligonucleotides to convert the absorbance readings into mass (µg/ml) and molar (pmol/µl)
concentrations. You can input the molecular weight and molar extinction coefficient
directly if you know them, otherwise SmartSpec 3000 will use one of three methods to
estimate them for you: Length, Composition or Sequence. The simplest method to
estimate either the molecular weight or the molar extinction coefficient is by the length
of the oligonucleotide. This method assumes an equivalent distribution of all four
nucleotides among the oligo. More accurate estimates can be calculated if you specify
the composition (i.e., the number of A’s, C’s, G’s and T’s or U’s) of the oligo and the best
estimate of molar extinction coefficient is calculated with the sequence of the
oligonucleotide.
Press Select to change the default to Composition (Compstn) and press Select again to
set the default to Sequence.
5. Default number of sample replicates. SmartSpec 3000 has the ability to accept samples
(and standards) in replicate groups and to calculate a mean and standard deviation for
each sample (or standard) replicate group. The factory default number of sample
replicates is 1, but you can change the number of replicates to any number between 1 and 9.
Use the keypad to choose the number of sample replicates and press Enter or Setup when
finished. During most assays you can change the number of sample replicates by
choosing Options from the Ready Screen.
8
Substract A320 Background
for DNA/RNA? Yes >=Help
Select default type of
DNA/RNA: dsDNA
>=Help
Select default method of
find oligo conc: length
Enter default number of
sample replicates: