Using AI to accelerate biotech is fast becoming standard practice, and companies offering services to deploy the tech quickly are seeing big uptake and new investment. Cradle is one of these, focused on protein design — and it just raised $73 million to build out its labs and team.

Cradle appeared in 2022 as part of a wave of companies to exploring the use of language models in biotech. The company’s founder and CEO, Stef van Grieken, memorably referred to the strings of amino acids and bases as “an alien programming language,” but one that an AI model can still parse to some extent.

The company’s approach was to accelerate testing of large biomolecules like proteins (which serve countless purposes in medicine and industry) by attempting to find and recommend sequences that affect desirable qualities. So, if you have a useful protein but want it to be more resistant to heat, the model looks for sequences that tend to break down at warmer temperatures and offers alternatives that won’t change its functions otherwise.

After a $24 million A round in 2023, Cradle has been plugging away serving customers in the biotech and pharma spaces. Van Grieken said companies primarily value the acceleration and cost savings that come with having to do fewer experimental runs to get the molecule where they want it.

“Companies developing products like antibody therapeutics against a certain disease or enzymes for a detergent will typically run dozens of experimental rounds to improve the efficacy, safety, and manufacturability of their protein,” he said in an email to TechCrunch.

These experimental rounds can cost tens or hundreds of thousands of dollars and take a good deal of time. Not to mention the guesswork and luck that factor into it — while careful study and intuition contribute to the result, there is unavoidably a lot of unpredictability in this space, and any method of reducing it is welcome.

He also noted that their simple SaaS business model has proven popular, as there’s no need to worry about royalties, revenue share, or IP issues.

Competition, van Grieken noted, is split into two groups along those lines: those doing close partnerships to co-develop a drug or process, and those, like Cradle, strictly providing a software service. “We believe that AI in drug discovery and development will ultimately be a commodity and any team should have access to it,” he said.

But even though Cradle makes software, it’s still a biotech company.

“We have a laboratory in Amsterdam where we use to A/B test on many different types of proteins as well as develop ‘Foundational Datasets’ that help models learn properties of proteins that benefit all of our customers,” van Grieken said. And they must regularly train and fine-tune models from these datasets themselves, as well.

The $73 million round, led by IVP, with Index Ventures and Kindred Capital participating, will go toward building out the wet lab and hiring up all around.

“Our goal is now to put Cradle’s software into the hands of a million scientists,” van Grieken said in a press release.