X0306 4 2022-02-07 0 0001831915 Cytek Biosciences, Inc. CTKB 0001872873 Jiang Wenbin C/O CYTEK BIOSCIENCES, INC. 47215 LAKEVIEW BOULEVARD FREMONT CA 94538 1 1 0 0 President and CEO Common Stock 2021-12-04 5 G 0 E 5000 0.00 D 7842710 D Common Stock 2022-02-07 4 S 0 20000 14.40 D 7889375 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 6, 2021. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.01 to $14.73, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. Includes 66,665 shares received as a liquidation distribution from WYTJ LLC. In prior reports, the Reporting Person reported beneficial ownership of 2,666,600 shares of the Issuer's common stock held by WYTJ LLC. /s/ Valerie Barnett, Attorney-in-Fact for Wenbin Jiang 2022-02-09