Bio-Rad SmartSpec Plus Spectrophotometer - Manual (Page 29)

• After the default conversion factor is accepted or changed, SmartSpec Plus is ready
to measure nucleic acid absorbance and convert that absorbance to concentration.
B. DNA oligonucleotides and RNA oligonucleotides.
If you choose DNA oligo or RNA oligo, you must provide the molecular weight of the
oligo and either the molar extinction coefficient or the mass/absorbance conversion
factor. If you don’t know them, then SmartSpec Plus can estimate them for you.
• If you know the molar extinction coefficient, press Select to toggle from No to Yes
and press Enter. If you do not know the molar extinction coefficient, press Enter
and skip to ii below.
i. If you know the molar extinction coefficient.
• Use the number keys to input the extinction coefficient and press Enter.
Note: You must enter the molar extinction coefficient in units of liter mole
-1 cm -1 .
SmartSpec Plus will next prompt for the oligo molecular weight.
• If you know the molecular weight, press Select to toggle from No to Yes and press
Enter. If you do not know the molecular weight of the oligo, press Enter and skip
to b below.
a. If you know the molecular weight.
• Use the number keys to input the molecular weight and press Enter.
After you have entered the molar extinction coefficient and the molecular weight,
SmartSpec Plus will display them.
• Press > to continue the assay, and the screen will display
SmartSpec Plus is now ready to collect absorbance data.
26
Mol Ext Coef=xxxxxxx
MW=xxxxx >=Continue
Ready to read absorbance
<=Exit Assay >=Options
Do you know molecular
weight of oligo? No
Enter oligo molecular
weight: _________ g/mol
Enter molar extnctn coef
in L/mole/cm: __________
Ready to read absorbance
<=Exit Assay >=Options
Do you know oligo molar
extnctn coefficient? No