Clinical and Laboratory Standards Institute guideline PRE04—Handling, Transport, Processing, and Storage of Blood Specimens for Routine Laboratory Examinations discusses multiple variables that are involved in handling and processing blood specimens. Its application should enable the user to recognize and control accuracy and precision factors that occur between the time of blood collection and the time of examination performance.

This guideline replaces the previous edition of the approved guideline, GP44-A4, published in 2010. Several changes were made in this edition, including: 
• Combining common information on specimen handling, transport, processing, and storage to eliminate redundancy and/or potentially contradictory information across CLSI documents (NOTE: Detailed information for specific measurands and/or specimen types is retained in applicable CLSI documents.) 
• Describing in-vitro variables that can affect the integrity of blood specimens throughout the path of workflow 
• Adding specimen suitability criteria that consider each measurand to be examined 
– Conditions that are not suitable for one measurand may still be acceptable for others. 
• Adding information related to the quality system essentials (QSEs) described in CLSI document QMS01 
– The QSE-related content discusses equipment, including internal and external transport systems, refrigeration and freezer units, temperature monitoring systems, and nonconforming event management, which includes monitoring the occurrence of unsuitable specimens.

This guideline provides recommendations for appropriate handling, transport, processing, and storage of specimens used as whole blood, serum, or plasma for routine laboratory examinations. It is intended to cover the general principles of preserving and maintaining the in vivo characteristics of specimens so the laboratory can develop a discriminatory thought process for evaluating specimen integrity.

This guideline focuses on many of the variables related to the preexamination phase of the path of workflow that affect specimen quality. However, it does not include an in-depth discussion of collection considerations, such as proper patient preparation (eg, fasting status, time of collection, particularly for therapeutic drugs or measurands with diurnal variation), collection methods (eg, collecting specimens through intravenous catheters, length of time tourniquet is applied), and skill of the health care professional. These factors can also have a direct effect on the outcome of the eventual examination result. In specimen collection, nothing can replace the value of a properly identified patient and accurately labeled specimen to provide clinically useful information on which the health care provider (HCP) can base medical, diagnostic, and treatment decisions. See CLSI documents GP33 for patient identification and specimen labeling, GP41 for the venipuncture collection procedure, and GP42 for the capillary blood collection procedure.

The number of measurands and types of specimens used for medical laboratory examinations is broad. This guideline covers many of the measurands and specimen types in use. Although it includes new technologies and methodologies, it is not a comprehensive discussion of all possible blood specimen requirements. PRE04 also includes a detailed discussion of centrifugation and centrifuged specimen quality, taking into consideration the specimen collection tube, additives, temperature, time of applied force, and other conditions. In addition, guidance on temperature monitoring during transport is provided. This guideline can be used globally to standardize processes and to help laboratories meet accreditation and regulatory requirements related to maintaining the quality of blood specimens throughout the laboratory’s path of workflow.

This guideline can assist laboratorians and other health care professionals to recognize factors that affect specimen quality so that many sources of error can be minimized or eliminated before the specimen is affected. The recommendations focus solely on blood specimens, but the principles can be applied to specimens in other laboratory areas as well.

Regulatory and accreditation requirements for transporting hazardous or dangerous materials are only minimally discussed in this guideline. This guideline does not cover handling, transport, processing, or storage of:
• Nonblood specimens
• Blood gas specimens (refer to CLSI document C46)
• Coagulation specimens (refer to CLSI document H21)
• Specimens for point-of-care testing
• Blood culture specimens (refer to CLSI document M47)

In addition, this guideline does not include molecular pathology or molecular diagnostic testing of nucleic acids, DNA, or RNA from human cells, microbial cells, or viruses. See CLSI document MM13 for details related to molecular testing.