SNS - Performance: Supplemental Newborn Screen, Blood Spot

Test Catalog

Test Name

Test ID: SNS    
Supplemental Newborn Screen, Blood Spot

Method Description Describes how the test is performed and provides a method-specific reference

In the United States, every newborn undergoes state-mandated screening on the second day of life or before leaving the hospital. Blood from a heel prick is dripped onto a filter paper card. The blood is left to dry before sending the filter paper card along with pertinent demographic information to the screening laboratory.


Blood for the supplemental newborn screening is collected in the same way and then sent to the Biochemical Genetics Laboratory, after obtaining parental consent. A 1/8-inch (3-mm) disk is punched out of the blood spot onto 96-well plate. Then, the amino acids and acylcarnitines are extracted by the addition of methanol and known concentrations of isotopically labeled amino acids and acylcarnitines as internal standards. The extract is moved to another 96-well plate, dried under a stream of nitrogen, and derivatized by the addition of n-butanol hydrochloric acid. In a parallel process, succinylacetone is extracted from the residual blood spot, derivatized with an acidic hydrazine solution, evaporated and combined with the amino acid and acylcarnitine extract amino acids and acylcarnitines are measured as their butyl esters with the hydrazone derivative of succinylacetone by electrospray tandem mass spectrometry (MS/MS). The concentrations of the analytes are established by computerized comparison of ion intensities of these analytes to that of the respective internal standards.(Turgeon C, Magera MJ, Allard P, et al: Combined newborn screening for succinylacetone, amino acids, and acylcarnitines in dried blood spots. Clin Chem 2008;54:657-664)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.

Monday through Saturday; 9 a.m.

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

2 days

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

3 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded


Performing Laboratory Location The location of the laboratory that performs the test