![An external file that holds a picture, illustration, etc., usually as some form of binary object. The name of referred object is rmmj-5-1-e0001-g02.jpg](images\rmmj-5-1-e0001-g02.jpg)
Figure 2.
Neonatal Screening for SCID Using TREC Content.
The Guthrie card, used to collect heel-stick blood, is obtained routinely from every newborn. Quantitative PCR is performed from a 3-mm punch, and the number of TRECs is determined by comparison with standard serial dilutions of a plasmid containing the TREC sequence.