User manual

Section 4- Method Editor
• Additional Measurements - adds user-selected or user-defined formulas for additional processing of data.
Refer to “Creating New Formulas” below for additional details regarding how to build a custom formula.
• Instrument settings - selects the spectral display wavelength range for the method. The auto pathlength
option automatically uses the optimal pedestal pathlength for high concentration samples. It is
recommended that the auto pathlength feature be selected for most sample measurements.
- When selected, the optimal shorter pedestal pathlength is used when the specified analysis wavelength
has a 1 mm equivalent absorbance value >1.25. (For analysis nm between 190 to 219 nm, the change to
the shorter pathlength occurs at 1 mm equivalent absorbance values of >1.0.)
- When the auto pathlength is not selected, only the 1 mm pathlength is used. Concentrated samples may
result in jagged peaks indicating detector saturation.
• Standard - an additional tab that appears when a standard curve option is selected as the method type.
This tab is used to define the initial standard names and concentration values that appear in the custom
method and is used to define the curve fit used in the method. Curve fit choices include: linear, linear
through zero, interpolation, 2
nd
and 3
rd
order polynomials.
- The Standard tab is also used to define, save or recall a series of standard concentration values. Although
standard concentration values for a method can be entered within this page, the values may also be
entered or modified when the method is opened to make measurements. Absorbance data associated with
a set of standards is not entered or recalled using this feature.
- A standard curve can be generated using a minimum of two points which may include two standards or a
reference (assay buffer only – no protein) and one standard.
- The multi-point curve capability allows for multiple replicates for up to seven standards. There is no set
order in which standards must be run.
- Additional standards may only be added before unknown samples are measured. Once the first sample is
measured, no additional standards or replicates may be added.
- A standard may be deleted at any time before a sample has been measured. Right-click the results table
to the far right to delete a standard or clear the entire standards table. Right-click a standard within the
replicates table under the graph display to delete individual standard replicates.
- Deleted standards cannot be added back or re-measured once the first sample is measured.
- In order to establish a new standard curve, a new workbook must be created.
Creating New Formulas
The Additional Measurements tab is used to define measurements that are included in the report in addition to the
principle concentration setup on the Measurement tab of a method.
New measurement values are defined by entering the desired value name, the formula used to calculate the value,
and the unit of measure associated with the value. A formula can be keyed-in manually, selected from a list of
predefined formulas, or constructed from a set of equation templates using the “Build formula” button.
Each formula consists of a mathematical expression written in a form similar to that used in a computer language or
command script language. They are composed of constant values, arithmetic operations, a set of mathematical
functions, and functions that extract values from the sample data collected.
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