Bio-Tek ELx800, Operator'S Manual

Page: 204 / 214

176
|
Appendix E: Instructions for Programming a New Assay
Quality Control and Results
Quality Control
For an assay to be valid, all the following criteria must be met:
• Cutoff as well as Positive and Negative controls must be
included in each run.
• The OD of the cutoff and the ANA result of the Negative and
Positive Controls should be in the ranges specified on the QC
Certificate.
•
For example: The absorbance of the Positive Control must be
greater than 1.200 OD.
The absorbance of the Negative Control must be less than 0.300
OD.
Note: If the above criteria are not met, the assay is invalid and
the test should be repeated.
Calculation of the Sample Results
Use the following formula to calculate the ANA result for each sample:
Control or sample OD
x 10 = Control or sample value (U/ml)
Cutoff control OD
9
Expected Values
The normal range was determined on serum from 200 normal adult blood
donors. The cutoff control has been set at a point equivalent to the upper
normal limit, or a cutoff level of 10 U/ml.
The ranges are provided as a guide only. ELISA assays are very sensitive
and capable of detecting small differences in sample populations. It is
recommended that each laboratory determine its own normal range, based
on the population techniques and equipment employed.
ANA Result Interpretation
< 10.0 Negative
> 10.0 Positive
Bio-Tek Instruments, Inc.