Walter G. Guder 
Pre-Examination Procedures in Laboratory Diagnostics [PDF ebook] 
Preanalytical Aspects and their Impact on the Quality of Medical Laboratory Results

The preanalytical phase is an important component of Laboratory medicine and errors arising in this phase affect the validity of laboratory results. In this book physicians and clinical staff have access to valuable information about the current preanalytical variables and factors (patient preparation, sample collection, handling and processing before analysis).