[Construction and preliminary identification of subtracted cDNA library of leukemia cell line K562].

Objective: Subtractive hybridization technology is a common method to screen and clone differentially expressed genes. This study was to construct subtracted cDNA library of leukemia cell line K562, and screen for differentially expressed genes.

Methods: cDNA fragments of K562 cells (tester), prepared by restriction display (RD), were subtracted with the Sau3A I-digested cDNA fragments of normal lymphocytes (driver). The subtracted cDNA fragments were re-amplified, and cloned into pMD18-T vectors. Positive clones were selected by blue-white screening. The inserts in plasmid were amplified by polymerase chain reaction (PCR), and some of which were sequenced.

Results: The subtracted library contained 360 positive clones with cDNA fragments distributed mainly from 200 to 800 bp. The 50 randomly sequenced clones were derived from 42 known genes.

Conclusion: Specific subtracted cDNA library of K562 cells was successfully constructed with reliable quality, and may be used to further screen and clone differentially expressed genes of K562 cells.