Guthrie card

A punched out piece of the Guthrie card is incubated in 50 pi of distilled water for 10 min at room temperature. A 10-pl aliquot of Fe(III)-citrate (200 pM) and 50 pi of distilled water are added to the sample and incubation is performed for 10 min at room temperature. One microlitre of the dissolved material is subsequently investigated by PhastGel electrophoresis as described above. 

In the case of unclear transferrin patterns obtained from IEF analysis of blood samples derived from Guthrie cards, the analysis should be repeated with serum. 

Screening for a BH4 deficiency should be done in all newborns with plasma phenylalanine levels higher than 120 pmol/1, as well as in older children with neurologic signs and symptoms [10]. The following tests are recommended (1) analysis of pterins in urine, (2) measurement of DHPR activity in blood from a Guthrie card,... 

Table 6.1.6 Reference values for pterins in amniotic fluid and dried blood (from a Guthrie card). A amniotic fluid, blood, Hb hemoglobin, Pie pterin...

DHPR activity may be determined from whole blood, RBC, dried blood from Guthrie cards, cultivated primary dermal fibroblasts, or from lysates of tissue samples (e.g., liver or brain). 

To prepare hemolysate dilute 50 pi of whole blood or resuspend 25 pi of RBC in 1 ml of 0.15 M KC1 and incubate for 30-40 min at room temperature for lysis. To prepare hemolysate from Guthrie cards, 4-6 circles with a diameter of 5 mm are cut... 

Nine kinds of sampling paper/cards were used. FTA Elute (Micro), FTA DMPK-B, FTA DMPK-A, Indicating FTA (pink), FTA Plant, Blood Stain, Protein Saver 903 (previously Guthrie Card or Schleicher Scheull Card in different times), and 31 ET were from Whatman (now GE Healthcare, Piscataway, NJ, USA) and VWR 237 filter paper from VWR International (West Chester, PA, USA). 

Fig. 2 Filter paper card ( Guthrie card ) for the collection of blood spots. ...

From a purely clinical or analytical chemistry perspective, the most unique aspect of NBS is the DBS. This special purpose filter paper was originally developed by Dr. Robert Guthrie to collect blood from the heel of an infant. It was developed as part of a bacterial inhibition screening assay for PKU [15], The DBS is also known as the Guthrie card or the PKU card. It is prepared from... 

Measurement of DHPR activity in blood from a Guthrie card... 

Phe free diet Guthrie card, serum/ keep cool (-20 C)... 

NBS is sharing with LC-MS/MS the same sample collection (filter paper collection and handling is now referred as dried blood spot (DBS)) and sometimes this creates some confusion in the terminology. For example, Guthrie card was intended to be the filter paper where blood is collected and today, with the adoption of LC-MS/MS, this definition is still used, even if LC-MS/MS has nothing to do with the Guthrie test (bacterial growth inhibition assay). 

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