biochrom ultrospec 7000 User Manual page 42

11.1.2. CyDye DNA
The measurement of the labelling efficiency of fluorescently labelled DNA probes
before 2-color micro-array hybridization ensures that there is sufficient amount
of each probe to give satisfactory signals. The data also provides an opportunity
to balance the relative intensities of each fluorescent dye by adjusting the
concentration of each probe before hybridization. The DNA yield is measured at
260 nm whilst the incorporation of the dyes is measured at the absorption maxima.
This method is also useful for measuring the yields and brightness of fluorescently
labelled in-situ hybridization probes.
Measurement Parameters
Number of Dyes, this can be set to 1 or 2. Dye 1 Name allows the user to select
the dye used in the measurement, the Ultrospec 7000/8000/9000 have 19 dyes
pre-programmed and the option for user entry using the Custom Dye option. λ
Max, Extinction Coefficient and Correction Factor are only editable when using the
Custom Dye option.
You may advance to the next screen at any time by pressing the forward arrow
and return to the previous screen by pressing the back arrow.
With Number of Dyes set to 2, the next method parameter screen allows the user to
specify the second dye used in the measurement.
If the measurement requires the calculation of DNA Concentration and/or DNA
Quantity the relevant nucleic acid can be inputted. A custom factor can be entered
by selecting Custom in Nucleic Acids.
This parameters screen allows the user to set the pathlength of the cuvette being
used, whether background correction is required and at what wavelength, the
dilution factor and volume of the sample in µl. All of these will be used in the
calculations.
Bandwidth (Ultrospec 9000 only), Integration Time and Lamp Mode can be set as
you wish. The Sample Seed entered under Sample will the filename of any saved
file.
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