<P> The classical Guthrie test is named after Robert Guthrie, an American bacteriologist and physician who devised it in 1962 . The test has been widely used throughout North America and Europe as one of the core newborn screening tests since the late 1960s . The test was initially a bacterial inhibition assay, but is gradually being replaced in many areas by newer techniques such as tandem mass spectrometry that can detect a wider variety of congenital diseases . </P> <P> The blood samples can be used for a variety of metabolic test to detect genetic conditions, including: </P> <Ul> <Li> Galactosemia </Li> <Li> Immunoreactive trypsinogen to detect cystic fibrosis . </Li> <Li> Maple syrup urine disease (MSUD or Branched Chain Ketonuria) a rare disorder where an error in metabolism inhibits the breakdown of amino acid leucine, isoleucine and valine . It can impair brain development . </Li> <Li> Medium - chain acyl - coenzyme A dehydrogenase deficiency (MCADD) </Li> <Li> Phenylketonuria, a disorder where an error in amino acid metabolism can impair brain development (PKU) </Li> <Li> Sickle - cell disease </Li> <Li> Thyroid stimulating hormone (TSH) to detect congenital hypothyroidism and hence prevent cretinism . </Li> </Ul> <Li> Immunoreactive trypsinogen to detect cystic fibrosis . </Li>

When do they do the heel prick test