Method for forming full-length cDNA libraries

A method for making full-length cDNA libraries, which is for making libraries of cDNAs having lengths corresponding to full lengths of mRNAs and comprises the following steps of:

• forming RNA-DNA hybrids by reverse transcription starting from primers using mRNAs as templates, followed by
• binding a biotin molecule to a diol structure present in the 5' Cap (.sup.7Me G.sub.ppp N) site of a MRNA which is forming a RNA-DNA hybrid,
• digesting RNA-DNA hybrids binding biotin molecules with an RNase capable of cleaving single strand RNA to cleave the single strand RNA parts of the hybrids carrying a DNA not corresponding to a full-length mRNA to remove biotin molecules from the hybrids, and
• separating hybrids carrying a DNA corresponding to a full-length mRNA and binding with a biotin molecule by allowing them to react with avidin or streptavidin fixed on a solid support.

A method for making full-length cDNA libraries, which is for making libraries of cDNAs having lengths corresponding to full lengths of mRNAs and comprises the following steps of:

• forming RNA-DNA hybrids by reverse transcription starting from primers using mRNAs as templates, followed by
• binding an avidin or streptavidin molecule to a diol structure present in the 5' Cap (.sup.7Me G.sub.ppp N) site of a mRNA which is forming a RNA-DNA hybrid,
• digest in g RNA-DNA hybrids binding avidin or streptavidin molecules with an RNase capable of cleaving single strand RNA to cleave the single strand RNA parts of the hybrids carrying a DNA not corresponding t o a full-length mRNA to remove avidin or streptavidin molecules from the hybrids, and
• separating hybrids carrying a DNA corresponding to a full-length mRNA and binding with an avidin or streptavidin molecule by allowing them to react with biotin fixed on a solid support.