Abstract: A human chromosome pq34 region-specific, microdissected library was constructed by using laser microdissection techniques. This library contains over 10,000 clones with an average insert size of 450 bp. It has greater coverage of the dissected chromosome region as compared with the needle-dissected chromosome 9q34 library. The laser microdissection technique provides more accurate chromosome targeting and easier operation than existing needle microdissection techniques. To simplify the procedure for chromosome microdissection and chromosome fragment collection, a trapping-cutting system was developed. This technique involves the use of two trapping beams which hold a single chromosome in suspension, and a third cutting beam, which dissects the immobilized chromosome. A collection chamber allowing for the fast collection of dissected chromosome fragments needs to be developed. However, DNA can be cloned from trapped chromosome fragments with an insert size comparable to that of both needle-cut and laser-cut chromosomes.