Chromate 4300 - Page 34

30 ChroMate™ Operator’s Manual Doc. 4300 Rev. E
Cutoff (Continued): Description (Continued):
¾ COV = X*mean (NC) + Y*mean (Pc) + F
• Use this equation when ChroMate must
calculate the cutoff value based upon
readings or positive and/or negative
controls.
• In this equation, NC and PC are used to
determine the COV (cutoff value).
• Enter the variables provided in the
package insert.
• ChroMate calculates the mean of the
positives and the mean of the negatives.
¾ COV = X*mean (Cc) + F
• COV = cut off value for positive or
negative interpretation
• X = a variable provided in the Assay Kit
package insert. NOTE: X will equal 1 if
no value of variable provided.
• mCC = the calculated mean of the
absorbance values of the cutoff controls
when test is run
• Blanking is optional, dependent upon the
Assay Kit
• F = factor added to the mCC. If needed,
this value is provided in the Assay Kit
package insert. If none provided, use
zero for the value of F.
• Positive and/or negative controls may be
used for QC criteria.
The user may choose either the regular
cutoff mode (positive >= cutoff, negative <
cutoff), or the reverse cutoff mode (positive
<= cutoff, negative > cutoff). The instrument
calculates the mean of the positives and the
mean of the negatives.
User programmable QC Criteria is available
on all controls.