Amidst a slew of disappointing IPOs, the moderate success of Genomic Health's IPO signals investor interest in a new diagnostics model: a combination product/service business -- technologically agnostic -- focused on coming up with an answer to a specific yes/no question that will either lead to or discourage an expensive therapy by a specialty physician audience. Several other start-ups are following the same model.

VCs won't go near traditional diagnostics. But some are starting to bet on biomarkers that expedite drug R&D and commercialization. Only one problem: they've yet to come up with the right business model

Five years after the genomics bubble burst and financing doors shut, a small window may be opening for research tool suppliers that help pharma improve R&D efficiency and cost structure. But clinically-oriented research companies face particular challenges, notably how to build a business where customer adoption is slow but technology is evolving rapidly and investors are impatient.

Accepted in discovery, microarrays are paving the way for biomarker development and eventually, molecular diagnostics.