[Isolation of the expression fragments with the probe pool of human chromosome 14 q 24.3 generated by microdissection].

The strategy of isolating the band-specific expression fragments from the probe pool of human chromosome generated by microdissection was reported in present paper. A chromosome 14 q 24.3 band-specific single copy DNA library was constructed based on this probe pool. Using this pool DNA as probe to hybridize the human bone marrow cell cDNA library, 68 primary positive clones were selected from 5 x 10(5) cDNA clones. Of them 32 clones were got in second-round screening and designed as cFD 14-1-32. Finally, 24 bandspecific expression fragments were identified from these 32 positive clones by analysing the results of DNA hybridization. Those band-specific clones can hybridize to both 14 q 24.3 DNA and human genomic DNA, but have no hybridization signal with 17 q 11-12 DNA. Partial sequences of 13 fragments of them were sequenced and were identified as novel cDNA sequences as well as have some homology with known genes in NCBI database. Analysis of expression spectrum of cFD 14-1 suggested that the cDNA fragments thus obtained can be used to isolate the genes not yet be cloned in 14 q 24.3 region.