At present MPDB contains the description of more than 4000 oligonucleotides having a length between 10 to 100 bases. Information is recorded in the following predefined fields: Tipology, Sequence, Organism, Target Gene, Application, Methods, Technical Data and Bibliography, In the last year we have added new items under the fields ''Applications'' and ''Tipology'', and we have inserted a new field, the ''Methods''. Our modifications consider the recent developments of the molecular biology research, under the field ''Tipology'' we have listed the items ''Probe'' (PB), ''Primer'' (PM), ''Antisense Oligonucleotides'' (AS) and ''Peptide Nucleic Acid'' (PNA).

The Molecular Probe Data Base (MPDB) was carried out in order to collect and make available on-line information on synthetic oligonucleotides. It was developed within the Interlab Project, as part of the improvement of Italian research infrastructures. Major improvements have recently been made in the Molecular Probe Data Base both in terms of data content and new means of data access. At present MPDB contains information on 3000 oligonucleotides specific for 672 different genes including 573 human and 91 viral genes; about 2500 oligonucleotides are specific for human genes, while 441 recognize viral genes. MPDB was implemented by means of the Oracle (TM) relational database system. In this paper we presented recent results concerning applications for data insertion, update and searching.

Molecular Probe Data Base contains detailed information on synthetic oligonucleotides with a sequence of up to 100 nucleotides. This database prevalently contains information related to human oligonucleotides used in diagnostics. Molecular Probe Data Base has been made available on-line through the Internet by means of Network Information Retrieval (NIR) tools since 1993. Two years ago, a collaboration with EMBL Data Library was also set up, so that the Molecular Probe Data Base has been integrated with other molecular biology data banks in the sphere of the SRS WWW network browser. In this paper, the most recent enhancements and the current status of the Molecular Probe Data Base are briefly presented.