Abstract: Method and device for the in vitro analysis of mRNA of genes involved in hematological neoplasias. The device, composed of probes which specifically hybridize with genes involved in hematological neoplasias, designed so that its behaviour in the hybridization is similar, permits the evaluation of the mRNA level in biological samples taken from subjects suspected to be suffering from hematological neoplasia and facilitating the comparison between the different samples and their grouping by similarity in the gene expression patterns, especially when the probes are disposed in the form of microarray. The application of the method of the invention to obtain and process data of gene expression differences from the device of the invention permits the identification of genes significant for distinguishing samples associated to hematological neoplasias, facilitates the diagnosis of neoplasias as CLL and permits making a prognosis of the evolution thereof.