Bio-Rad SmartSpec Plus Spectrophotometer - Manual (Page 23)

2. Choose sample replicates. Samples may be read in replicate and you do not need to
have the same number of replicates for each different sample. For each sample replicate
group, SmartSpec Plus will calculate a mean absorbance and standard deviation. When
the full report is printed, each individual absorbance is reported along with the mean
and standard deviation of the replicate group. If the default number of sample replicates
has been set to 2–9 (in Setup), then SmartSpec Plus will ask if any of the samples in
this assay are to be read in replicate. The default answer is No.
• If you want to read samples in replicate, press Select to toggle from No to Yes and
press Enter. You do not need to have the same number of replicates for each sample.
• Use the number keys to enter the number of sample replicates. The default num-
ber is the number chosen in Setup.
The default number of sample replicates can be changed during the course of the assay
by choosing Options from the Ready screen.
3. Set the dilution factor. The dilution factor is reset to 1 each time an assay button is
pushed. The dilution factor is always a number greater than or equal to 1; if one vol-
ume of sample has been diluted with nine volumes of buffer, the dilution factor is
entered as 10.
• Use the number keys to input the dilution factor and press Enter.
4. Zero the spectrophotometer. Zero (blank) SmartSpec Plus by placing a cuvette
containing the sample solution without analyte into the instrument and pressing Read
Blank. You can zero the instrument at any time during an assay.
5. Collect absorbance data. SmartSpec Plus is now ready to collect absorbance data and
convert them to concentration. Irrespective of whether you are going to read your samples
in replicate or not, the Ready screen will be displayed.
A. No sample replicates.
•
Place your first sample in the cuvette chamber and press Read Sample. After the
absorbance data are collected, they will be displayed as described below. At this
point, you can put your second sample into the cuvette chamber and press Read
Sample.
• If you wish to begin reading samples in replicate, first return to the Ready screen
by pressing Enter
and then press the right arrow key to choose Options.
20
Ready to Read Absorbance
<=Exit Assay >=Options
<=Change next sample #
>=Change # of replicates
Ready to Read Absorbance
<=Exit Assay >=Options
Enter a dilution factor:
Are any samples to be
read in replicate? No:
Enter number of sample
replicates # 3