The agreement will allow Sera to leverage LabCorp's sales force and networks, but similar deals have failed to deliver for proteomics firms in the past.
Sera plans to make the test for preterm birth available nationwide this year with LabCorp as the exclusive US distributor.
A health-economic model of the company's preterm birth test found it could lower infant mortality by 23 percent and yield annual savings of around $500 million.
According to one physician familiar with the test, it is a much needed diagnostic tool, but without insurance coverage it is too expensive for wide use.
Published this week in AJOG, the study found that the test could predict delivery before 37 weeks with 75 percent sensitivity and 74 percent specificity.
The mass spec-based proteomic test identified women who gave birth at or before 35 weeks gestation with an area under the receiver operating curve of .93.
This fall the company is rolling out a limited commercial launch of the MRM mass spectrometry-based proteomic test, with a broader launch to come next year.
With the additional funding, Sera aims to develop new tests for predicting the risk of preterm birth in women in developing countries, the company said.
The firm is validating the test and expects results to be available in the second quarter of 2015 with commercial launch of the test following around mid-year.
The funding follows a $19.3 million Series A round Sera closed in 2011 and will support development of its proteomic test for assessing women's risk of preterm delivery.
In Science this week: intellectual property landscape of CRISPR genome editing, and more.
A researcher has been convicted of conspiring to steal genetically engineered rice, Reuters reports.
Harvard Medical School's George Church says a woolly mammoth-elephant hybrid is only a few years away, according to the New Scientist.
Intel is ending its sponsorship of the International Science and Engineering Fair, the New York Times reports.