1. Low ODs for the Calibrators
   

   Possible cause	Resolution
   Reagent temperature	Use reagents at room temperature.
   Plate shaker	Set the plate shaker to a speed of 600 rpm.
   Plate sealers	Do not use during any of the incubation periods.
   Wells overdrying	Reduce time between wash step and addition of next reagent or use a 96-well washer instead of a strip washer.
   Substrate	Use correct volume of substrate.
   Plate reading	Read plate immediately after adding stop solution.
   Incubation time	Incubate for the recommended times.

2. Controls Out of Range
   

   Possible cause	Resolution
   Control or calibrator storage	Store controls or calibrators in ice during use.
   Incubation times or temperatures	Follow protocol for precise incubation times.
   Plate washing and drying	Do not allow plate to overdry after wash step.
   Detergent present in the wash	Use only deionized water.

3. Results Drift Across the Plate
   

   Possible cause	Resolution
   Time elapsed while loading the plate	Load samples within 20-25 minutes. Use a transfer plate to minimize delays. Have all reagents ready in advance to avoid interruptions.

4. Poor Precision of Replicates
   

   Possible cause	Resolution
   Plate washing step	Ensure that plate is washed 4 times per step and that the plate washer is functioning properly.
   Pipetting	Verify that volumes and pipette calibrations are correct.
   Plate shaker	Verify that plate shaker is set at 600 rpm.

The PLAC® test is currently available at some of the leading clinical reference laboratories in the nation:

Quest Diagnostics Incorporated
www.questdiagnostics.com
1-800-553-5445

LabCorp
www.labcorp.com
1-800-762-4344

Mayo Medical Laboratories
www.mayoreference
services.org/mml
1-800-533-1710

ARUP Laboratories
www.aruplab.com
1-800-522-2787

Berkeley HeartLab, Inc.
www.berkeleyheartlab.com
1-877-4-LIPIDS