Strauss Borrelli PLLC, a leading data breach law firm, is investigating Cytek Biosciences, Inc. (“Cytek”) regarding its recent data breach. The Cytek data breach involved sensitive personal information and protected health information belonging to an undetermined number of individuals.
ABOUT CYTEK BIOSCIENCES, INC.:
Cytek is a flow cytometry manufacturer and supplier based in California. Today, Cytek provides services and instruments to researchers and clinicians for use in flow cytometry, which is a tool used for identifying and quantifying cellular characteristics in applications such as diagnosing leukemia and lymphoma, investigating the roles of the body’s immune system in fighting cancer, and more.2,3 Headquartered in Fremont, California, Cytek employs over 500 individuals.3
WHAT HAPPENED?
Recently, Cytek reported to the Attorney General of Maine that it had experienced a data breach in which sensitive personal identifiable information and protected health information in its care may have been compromised. According to the breach notice, on or around November 1, 2025, Cytek experienced a data security incident involving unauthorized access to certain of its systems.1 As a result, Cytek launched an investigation to determine the nature of the incident.
Through its investigation, Cytek confirmed that sensitive personal information in its systems may have been accessed and acquired by an unauthorized third party during the breach. As a result, Cytek began a review of the data to determine what information had been impacted as well as identify the specific individuals affected. While the information impacted varies depending on the individual, the type of information potentially exposed includes:
- Name
- Social Security number
- Contact information (postal address, email address, phone number)
- Date of birth
- Driver’s license number
- Government-issued ID number
- Citizenship status
- Signature
- Health and medical information
- Financial account and compensation information
- Cytek employee account username and password
On December 22, 2025, Cytek began mailing data breach notification letters to impacted individuals. Based on the breach notice sent to Maine residents, Cytek is providing affected individuals with a list of the specific types of sensitive information impacted and 24 months of complimentary credit monitoring services. A link to the form breach notification letters that Cytek filed with the Attorney General of Maine is below.
If you received a breach notification letter from Cytek Biosciences, Inc.:
We would like to speak with you about your rights and potential legal remedies in response to this data breach. Please fill out the form, below, or contact us at 872.263.1100 or sam@straussborrelli.com.
