AIM:To construct a cDNA subtractive library of differential response genes of human fetal hepatocytes after HBV infection with suppression subtractive hybridization technique, and then to clone and identify the new genes that only express in HBV infected hepatocytes.

Then a subtractive library of the implantation site was successfully constructed by suppression subtractive hybridization (SSH).

In order to obtain an efficient subtractive cDNA library with larger fragments of age related cataract, an improved subtractive hybridization with biotin labeling and magnetic bead isolation to obtain the subtractive cDNA was used.

In order to obtain a quality subtractive cDNA library of age related cataract which contains more large fragments from small amounts of sample, an improved subtractive hybridization which using magnetic beads isolation and biotin labelling was used to obtain the subtractive cDNA.

The skin follicle subtractive cDNA library of the Inner Mongolian cashmere goat was constructed by suppression subtractive hybridization.

The cDNA subtractive library of the mantle of abalone vitamin E deficiency-treated was constructed using the method of suppression subtractive hybridization(SSH).

20 differential ests(expressed sequence tags) which are associated with the production of citrinin were screened from a cDNA subtractive library of Monascus through bioinformatics software,then BLAST software was applied to perform the homologous alignment and functional analysis of them.