Quantitative assays of enzyme activity in single cells: early prenatal diagnosis of genetic disorders.

The combined use of special cell culture techniques and biochemical ultramicromethods permits 
one to handle very small amounts of materials, to reduce the 
costs of chemicals, and more accurately to assess gene dosage effects 
by expressing enzyme activities per cell instead of per total cell 
protein. An alkaline phosphatase induction test has been developed which allows 
one to screen small numbers of fibroblasts for lysosomal storage diseases, 
cystic fibrosis, and chromosomal disorders. A successful attempt has been made 
to automate the microtechniques. Combining the alkaline phosphatase induction with the 
ultramicro automatization should eventually permit one to screen all pregnancies for 
major possible fetal genetic defects. Automated ultramicro enzyme assays should contribute 
to the general development of clinical chemistry. 