Letter: Bioassays of cystic-fibrosis factor.

We wish to respond to the letter of Dr. Woods and Dr. 
di Sant'Agnese regarding their study on the reliability of the ciliary 
assays in cystic-fibrosis screening. These investigators concluded that results from their 
study ruled out the possibility that reliable conclusions could be obtained 
from ciliary assays. We feel that this conclusion is far from 
accurate, although it has never been the intention of any of 
our research groups to utilise ciliary preparations for massive heterozygote screening 
or prenatal diagnosis. Ciliary assays have provided valuable scientific progress in 
cystic fibrosis research. The existing assays are not suitable for massive 
screening for cystic fibrosis or for the clinical detection of cystic-fibrosis 
carriers; nevertheless, these techniques offer the most promising method to study, 
purify, and characterise a molecule or molecules directly or indirectly related 
to the pathogenesis of cystic fibrosis. 