Barcode

Make sure the reader is clean.  Make sure you place the end of the barcode label up against the tube cap if you are using the hemogard caps.  Make sure the tubes are fitting into the rack snugly so they don't turn around any as the rack moves through the analyzer.  If you have an issue with the tubes turning, you will need to get the adapters for the racks that have the plastic clip that sticks down.