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