New methods for the detection of genetic variation.

The possibility to detect variations in the genetic material is limiting to measure DNA sequence variations occurring at low frequency, such as somatic mutations responsible for the generation of diversity in the immunoglobulin genes. In order to study mutations, a system has been developed using transgenic mice in which mutant genes are rescued and selected among non mutant genes by the phage lambda as shuttle vector. Moreover, it has been developed a two-dimensional DNA fingerprinting method based on the capacity to separate digested DNA on the size and base sequence.