Pre-analytical variables are those that affect the specimen before the actual testing begins. Some of the pre-analytical variables to consider with molecular testing include those that are applicable to all clinical specimens but should be emphasized when discussing molecular methodologies; some of these include but are not limited to:
Receipt of valid order
Proper patient identification
Proper venipuncture procedure for blood collection
Use of correct anticoagulant
Collection of correct specimen type (i.e.- plasma, serum, whole blood)
Order of draw
Proper storage
Proper transport
Procedures if there is a delay in testing and/or transport