Skystone currently owns 15.4 per cent of Harvard Bioscience provider and made a $5 (€3.5) per share offer to take the company private on Friday.
Harvard's board has unanimously rejected the offer which marked an 11 per cent premium on the current share price of around $4.50.
Harvard Bioscience is perhaps best known for its high-performance automated liquid injectors that are commonly used to introduce liquid samples into mass spectrometers when using electrospray ionisation (ESI) techniques.
Harvard Bioscience has achieved compound annual revenue growth rates of around 23 per cent per year, reaching sales of $76m (€52.8m) in 2006 and believes the $5 per share bid undervalues the company.
"After careful analysis and consideration, the Board determined that Skystone's offer undervalued Harvard Bioscience," said Chane Graziano, Harvard Bioscience's CEO.
"We believe our current strategy of combining tuck-under acquisitions with organic growth can deliver better value to all our stockholders than the Skystone offer."
Skystone has said it would consider increasing the offer price after completing due diligence should Harvard Bioscience provide additional information demonstrating a greater market value.
"We believe the recently announced launch of our microlitre spectrophotometer and the acquisition of Panlab confirms we are implementing this strategy," continued Graziano.
"In addition, we believe the recently announced divestiture of the majority of our capital equipment division will enable us to focus more management attention on our growth strategy."
At the beginning of the month, Harvard completed the sale of its Genomic Solutions division and its Belgian subsidiary, Maia Scientific, to Digilab for $1m cash plus additional consideration "in the form of an earn-out based on 20 per cent of the revenue generated by the acquired business as it is conducted by Digilab over a three-year period post-transaction".
The divested companies comprised the majority of Harvard's Capital Equipment business segment and their sell-off "will enable Harvard Bioscience management team to focus our resources on our apparatus and instrumentation business and to continue our pursuit of tuck-under acquisitions."
News of the divestiture was quickly followed by the announcement that the Board had authorised a $10m common stock repurchase programme to take place over the next two years, which "confirms [the Boards] optimism about the future prospects for the company."