The authors have used the modified method of the direct gene cloning suggested 
by Nichols et al to isolate HLA-B27 gene from a patient suffering from 
ankylosing spondylitis. Five restriction enzymes (ClaI, HindIII, SnaBI, PvuI, 
SalGI) which had no recognition sites within the 6.0 kb EcoRI-BamHI-DNA fragment 
supposedly containing the HLA-B27 gene have been chosen by 
blotting-hybridization of the restriction fragments of the patients DNA with 
HLA-B27-specific probe. The 6.0 +/- 0.5 kb DNA fragments were isolated and 
cloned after the DNA treatment by 300 micrograms of all of these restriction 
enzymes. The obtained mini-library containing 280 recombinants has been screened 
with the use of HLA-B27 specific oligonucleotide probe. The clone PB27-2 has 
been isolated the restriction map of which is identical to HLA-B27k. The authors 
are planning to determine the sequence of the isolated gene in order to find a 
possible structural defect in it.