* Repligen Corp., of Needham, Mass., formed a second collaboration with Pfizer Inc., of New York, for discovery of small molecule compounds that stimulate immune system responses. Financial terms were not disclosed. Repligen and Pfizer entered a partnership in 1996 to identify growth factor inhibitors.
* Vysis Inc., of Downers Grove, Ill., received FDA approval to market its Chromosome Enumeration Probe (CEP) 12 SpectrumOrange DNA Probe Kit. The in vitro diagnostic is used an adjunct to standard cytogenetic analysis for detecting the presence of trisomy 12, a chromosomal abnormality related to the B cell chronic lymphocytic leukemia. CEP 12, Vysis said, uses the company's fluorescence in situ hybridization technology.