NEURAMINIDASE ASSAY IN CULTURED HUMAN FIBROBLASTS - IN-SITU VERSUS IN-VITRO PROCEDURES

Further investigations have been carried out to characterize a publish ed procedure of neuraminidase assay, in which the activity is measured directly on the cell culture layer. The pH optimum was 4.0. A V-max v alue of 130 nmol/mg/h and a K-m of 0.3 mmol/l were found. During incub ation in the acid buffer, arylsulphatase activity was released into th e medium, whereas neuraminidase activity remained attached to the cell s. The in situ method allowed an unequivocal diagnosis of primary and secondary neuraminidase deficiencies. Because of its simplicity and re liability, the method appears useful as a routine method in clinical l aboratories.