scope:

Specimen Quality

The primary goal of this standard is to improve and ensure the quality of blood spots collected from newborns.¹ Unacceptable and poor quality specimens place an unnecessary burden on the screening facility, cause unnecessary trauma to the infant and anxiety to the infant's parents, potentially delay the detection and treatment of the affected infant, and could contribute to a missed or late diagnosed case. When the screening laboratory receives an unacceptable specimen, it should request another specimen according to criteria established by the testing laboratory. In all newborn screening programs, the turnaround time for analytic results is critical if treatment to prevent the adverse consequences of the condition (such as irreversible mental retardation or death) is to begin on time. For more specific information about newborn screening follow-up, refer to the most current edition of the companion CLSI guideline I/LA27-Newborn Screening Follow-up.

Specimen Acceptability

The only justification for refusing to analyze a specimen and declaring it unacceptable is that its analysis might yield unreliable, misleading, or clinically inaccurate values for a particular analyte. Since, by this definition, an unacceptable specimen gives no usable information, such specimens should not be analyzed, and those responsible for collecting the original specimen should be notified with all due haste so an acceptable specimen can be obtained as soon as possible. If a specimen is analyzed, the laboratory is, in effect, acknowledging that the specimen is suitable for testing and is assuming responsibility for the reliability of the analytic values. Program-specific rules should be written and followed consistently with respect to handling specimens of insufficient quantity, especially for multianalyte test panels.

Other Considerations

The secondary goals of this standard are to delineate the minimum necessary information for the specimen collection form; standardize the components of this form; describe minimal requirements for the filter paper matrix on which the blood spots are collected; and define the handling, shipping, retention, and storage conditions for dried blood spot specimens.

Applications

This standard specifically addresses the collection of blood specimens for newborn screening programs¹ and applies to the collection of specimens used to detect congenital conditions (e.g., aminoacidopathies, fatty acid oxidation and organic acid disorders, endocrinopathies, hemoglobinopathies, cystic fibrosis, infectious disease). Many aspects of this standard are also appropriate and useful for the collection of dried blood spots used for DNA/RNA molecular methods, home collection devices, and a variety of new tests. In addition, most elements of this standard are applicable to blood collection on filter paper from fingerstick punctures of adolescents and adults. With older children (greater than one year of age) and adults, the palmar surface of the finger's last phalanx is most frequently used. (See the most current edition of CLSI/NCCLS document H4-Procedures and Devices for the Collection of Diagnostic Capillary Blood Specimens.)