Following laboratory investigations were included in the screening protocol - dicts test for reducing substances, Ferric chloride test for
Phenylketonuria, Dintrophenylhydrazine test for alpha keto acids, Nitrosonaphthol test for tyrosine, Para nitroaniline test for methylmalonic aciduria, Cyanide nitroprusside test for cysteine and homocysyteine, Ammoniacal silver nitrate test for homocysteine, Thin layer chromatography for amino acids.