We describe a method for determining free and total cholesterol in extracts of rat-liver lipids by use of a cholesterol esterase/cholesterol oxidase enzymatic kit (Boehringer Mannheim Corp). The lipids are solubilized (as micelles) directly into the aqueous reagent mixture. Results of the enzymatic method correlate well with those obtained by an acid/ferric chloride assay of digitonin precipita...

Histone acetyl-transferases (HATs) seem to be key elements in the regulation of transcription. We have designed an enzymatic assay to quantify HAT enzymatic activity. In this assay, the substrate is a peptide corresponding to the 24 first amino acids of histone H4 which is coupled to biotin. After acetylation using [14C]acetyl-CoA, the peptide is purified on streptavidin beads and the associate...

Phenylketonuria (PKU) is an autosomal recessive disorder, which is characterized by severe mental retardation, microcephaly and seizures. The symptoms of this disease can be prevented if detected soon after birth. Therefore, blood Phenylalanine (Phe) measurement is essential for the early diagnosis, treatment and dietary monitoring of PKU patients. The goal of this research was to introduce a r...