How Colossal Biosciences Uses CRISPR and the Safeguards Behind the Science

Colossal uses a phased validation process before edited cells advance to embryos, including computational modeling, organoid testing, and cellular confirmation, such as whole genome sequencing and karyotyping. Animal welfare is a decision gate for which edits are pursued. After birth, animals are managed in a controlled care setting with longitudinal monitoring and clear intervention protocols, and key datasets and welfare documentation are shared publicly.

When Colossal Biosciences created functionally de-extinct dire wolves with 20 precise genomic edits across 14 genes, the achievement demonstrated more than biotechnology prowess. It revealed a comprehensive safety framework prioritizing animal welfare, rigorous validation, and conservation applications. Understanding how Colossal uses CRISPR, and the safeguards embedded in every step, reveals a deliberate approach to developing technologies that can help endangered species worldwide.

Traditional gene editing requires sequential modifications across multiple generations. Each edit stresses cells, and stacking changes compounds variables with each iteration. Colossal developed multiplex gene editing, enabling dozens of changes to be made simultaneously in a single intervention.

“Each time you edit a gene in a cell, you put a lot of stress on that cell,” explains Chief Science Officer Beth Shapiro. “So what we do instead is we try to make dozens or hundreds of changes at once.” This approach reduces overall cellular stress while increasing precision.

CEO Ben Lamm describes the validation: “We've developed a system so that we can deliver all of those edits at one time all over the genome, get exactly what we want, and then we have what's called monoclonal screening, where we're screening the cells at the end, sequencing all the cells.” Edited cell lines undergo comprehensive genomic analysis to screen for off-target edits or other unintended changes before advancing to downstream steps.

Colossal's safety framework operates through multiple validation layers before edited cells become embryos. This phased approach emphasizes prevention over intervention.

The process begins with computational modeling. Machine learning algorithms predict how specific edits will affect phenotypes, identifying potential problems before biological work begins. Organoid testing provides the next layer by growing tissue samples in laboratory dishes to observe edited gene expression without requiring live animals.

"If we grow an organoid that grows hair, can we see what that hair looks like without having to make a mammoth in order to see what that change is going to do?" Shapiro explains. Only after these tests confirm safety does work advance to cell-line experiments.

At the cellular level, researchers perform whole genome sequencing and karyotyping (comprehensive analyses examining not just whether intended edits occurred, but whether any off-target changes happened elsewhere in the genome). This scrutiny means Colossal can identify and discard any cell lines with unintended alterations before cloning.

The most critical safeguard is Colossal's explicit prioritization of animal welfare when selecting edits. Ancient dire wolf genomes revealed gene variants in three pigmentation genes predicted to confer lighter coats. However, when researchers explored these variants' potential impact on gray wolf genetic backgrounds, they discovered associations with albinism and hearing loss in dogs.

“That's not acceptable,” Shapiro states. “We know that there are pathways that make wolves white in a safe way. So we went with those edits rather than with the edits that evolved in dire wolves.” The team achieved the dire wolf's white coat using alternative genetic pathways that wouldn’t compromise health, choosing welfare over authenticity to extinct genomes.

This pattern repeats throughout editing. For the LCORL gene regulating body size, the team identified dire wolf variants predicted to alter protein folding. Rather than use ancient variants with uncertain effects, they selected variants already present in large gray wolf breeds, achieving similar size increases without additional risks. “We only proceed with an edit once we have strong certainty that it will be safe, and we always aim to make the fewest edits necessary to de-extinct the key phenotypes of an animal.”

Safety continues after birth. The controlled preserve enables longitudinal health monitoring tracking unexpected effects from multi-gene editing over lifespans. Researchers monitor cancer rates, immune function, epigenetic effects, aging patterns, and stress indicators, establishing a CRISPR safety baseline for large carnivores informing future conservation applications.

This managed care approach allows detection of off-target effects that might only appear during development or maturity. It provides data on how edited genes interact with complete organ systems. And critically, it maintains ability to refine or terminate the program if welfare concerns arise.

“We closely monitor and compare embryonic and fetal development against known and expected milestones in case there is ever a need for intervention.” The preserve's veterinary clinic, specialized staff, and continuous observation systems ensure immediate response capability.

The CRISPR techniques developed through functional de-extinction form part of a broader conservation toolkit integrating genome sequencing, computational biology and AI, biobanking, multiplex gene editing, disease mitigation, and assisted reproductive technologies.

Genome sequencing creates species-specific reference genomes enabling tailored conservation strategies. The Colossal Foundation is building high-quality reference genomes for endangered species worldwide, functioning as genetic maps researchers use to track population health and guide recovery efforts.

Biobanking preserves viable tissue samples from imperiled species in the distributed Colossal BioVault network, providing resources for future genetic rescue missions. This distributed system stores cell lines within countries where species live, respecting sovereignty while building global capacity.

Disease mitigation represents perhaps the most immediate gene editing application. The Colossal Foundation funded development of the world's first mRNA vaccine for elephant endotheliotropic herpesvirus (EEHV)—a lethal disease killing young Asian elephants. When two vaccinated elephants at the Cincinnati Zoo were naturally exposed in 2025, both showed no illness and recovered fully, providing real-world evidence that the vaccine saves lives.

The safety protocols developed for dire wolves already benefit endangered species. The birth of four critically endangered red “ghost” wolves, supported by de-extinction technologies developed through Colossal’s research, demonstrates how these approaches can translate into tools for living-species conservation.

Computational biology and AI extend the toolkit's reach. Colossal partnered with Save the Elephants to deploy thermal-equipped drones and machine learning models for passive tracking of elephant movements. The system identifies individuals, tracks sleep patterns, recognizes behaviors, and assesses health without invasive collaring.

Similar AI-powered bioacoustics work with the Yellowstone Wolf Project deploys autonomous recording units capturing and decoding thousands of wolf howls, revealing insights into communication, pack dynamics, and population trends while detecting threats in real time.

Colossal maintains transparency through multiple channels. All genomic edits undergo rigorous confirmation via whole genome sequencing, karyotyping, and bioinformatic analysis. The company openly shares methodologies through peer-reviewed publications. Key genetic datasets from the dire wolf research are publicly available through NCBI BioProject PRJNA1222369, enabling external scrutiny and follow-on research.

The comprehensive Dire Wolf Husbandry Manual is openly accessible, allowing external evaluation of welfare practices and establishing accountability standards.

Target quantitative success metrics make progress measurable: at least two conservation programs adopting genome editing or cloning methods by 2027, at least five scientific publications citing dire wolf genome datasets within three years, and zero containment breaches. These concrete benchmarks enable objective assessment of whether technologies deliver promised conservation benefits.

As Dr. Christopher Mason, scientific advisor and board observer, notes, “The same technologies that created the dire wolf can directly help save a variety of other endangered animals. This is an extraordinary technological leap in genetic engineering efforts for both science and for conservation.”

The CRISPR techniques and safety protocols developed through functional de-extinction aren’t endpoints. They are tools in an expanding conservation toolkit. By demonstrating that multiplex gene editing can be done safely, with rigorous validation, and with animal welfare as the primary consideration, Colossal is establishing standards for how biotechnology can responsibly support biodiversity conservation in an era of accelerating extinctions.