Normalization of a cDNA Library Cloned in λZAP by a Long PCR and cDNA Reassociation Procedure

250 BioTechniques Vol. 34, No. 2 (2003) be expected from an amplificationbased strategy. To our knowledge, this is the first time that such analysis has been conducted to assess the representation of a genomic library. In summary, we have developed a quick, facile protocol for constructing libraries from relatively small amounts of DNA. Using our method, we have shown that a representative, random library can be constructed in a single day. It has previously been shown that it is possible to vaccinate an animal using an entire genomic expression library and elicit a protective response (1). Therefore, it may be possible to create a genetic vaccine for even an unknown pathogen in a single day using this method. Given that in certain situations, such as biothreats or outbreaks of zoonoses, there may not be time to identify and isolate protective antigens from a complete genome, immunization with a shotgun random library may be a viable course of action.