X0508 4 2023-08-11 0 0001850906 Singular Genomics Systems, Inc. OMIC 0001535065 Kamdar Kim P. 3010 SCIENCE PARK ROAD SAN DIEGO CA 92121 1 0 0 0 0 Common Stock 2023-08-11 4 S 0 353657 0.5955 D 4041976 I By Domain Partners IX, L.P. Common Stock 2023-08-14 4 S 0 77991 0.5696 D 3963985 I By Domain Partners IX, L.P. Common Stock 2023-08-15 4 S 0 200000 0.5348 D 3763985 I By Domain Partners IX, L.P. Common Stock 15000 I By Domain Associates, LLC Common Stock 15000 D Domain Partners IX, L.P. has been an investor in the Issuer since 2016 and continues to hold 3,763,985 shares of the Issuer's common stock. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.58 to $0.67, 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 securities sold at each separate price within the ranges set forth in this footnote 2 to this Form 4. The Reporting Person is a managing member of Domain Associates, LLC and of One Partner Square Associates IX, LLC, the sole general partner of Domain Partners IX, L.P. Pursuant to Instruction 4(b)(iv) of Form 4, the Reporting Person has elected to report as indirectly beneficially owned the entire number of securities owned by each such entity; however, she disclaims beneficial ownership of any securities, and any proceeds thereof, that exceed her pecuniary interest therein and/or that are not actually distributed to her. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.55 to $0.5821, 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 securities sold at each separate price within the ranges set forth in this footnote 4 to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.53 to $0.54, 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 securities sold at each separate price within the ranges set forth in this footnote 5 to this Form 4. /s/ Dalen Meeter, Attorney-in-Fact 2023-08-15