Bio-Rad SmartSpec Plus Spectrophotometer - Manual (Page 44)

• You can choose to blank the instrument again before you re-read your sample by
pressing Enter at this screen. If you do not want to re-zero SmartSpec Plus, press
Select to toggle from Yes to No and press Enter.
SmartSpec Plus will now direct you to insert blank (if you chose that option above) and
the to insert the specified standard. When the absorbance data have been collected,
SmartSpec Plus will offer you an opportunity to continue re-reading other samples.
• If you want to re-read another sample, press Enter. Otherwise press Select to
toggle from Yes to No and press Enter.
• If you have completed the editing, press the left arrow key to return to the assay
and SmartSpec Plus will complete the calculation of the standard curve.
D. Completing the standard curve. SmartSpec Plus will now calculate the equation of
the new standard curve and offer you a chance to see the slope, intercept, and correlation
coefficient of the curve. All this information will be printed at the end of the assay if you
choose to print the full report. You may want to view the correlation coefficient before
completing the assay; if it is too far from 1.000, you may have constructed a poor standard
curve and the concentration calculations may not be very accurate. At the end of the
assay, you will be offered a chance to save the standard curve into memory for future
use, either as a standard curve or to compare to another standard curve.
After the last standard is read, you will see
and then once the calculations are completed.
• To view the correlation coefficient of the new standard curve, press Select to toggle
from No to Yes and then press Enter.
r2 refers to the square of the correlation coefficient and is a value between 0 and 1 with
1 representing a perfectly straight line (see discussion above). The general equation of
the curve fit is presented in the top right part of the display
Concentration = Absorbance*Slope + Intercept
• Press 0 to see the slope. Return to the assay by pressing the right arrow key.
41
Slope (M) = xx.xx exx
<=Back 0=More >=Continue
Want to view info on new
std curve now? No >=Help
r2=x.xxx CONC=ABS*M +I
0=Show more >=Continue
Calculating
Standard Curve
Continue rereading
Standards? Yes
1. Edit Concentrations
2. Reread a Std <=Back