SCHEDULE 13G/A 0000904454-22-000004 0001628864 XXXXXXXX LIVE 2 Common Stock, $0.0001 par value 12/31/2024 0001850906 Singular Genomics Systems, Inc. 82933R100 3010 Science Park Road San Diego CA 92121 Rule 13d-1(d) Domain Partners IX, L.P. a DE 0.00 125466.00 0.00 125466.00 125446.00 N 4.95 PN Domain Associates, LLC a DE 0.00 500.00 0.00 500.00 500.00 N 0.02 OO Singular Genomics Systems, Inc. 3010 Science Park Road, San Diego, CA 92121 This Amendment No. 2 to Schedule 13G is filed by Domain Partners IX, L.P., a Delaware limited partnership ("Domain IX"), and Domain Associates, LLC, a Delaware limited liability company ("DA" and together with Domain IX, the "Reporting Persons"). Reference is hereby made to the Schedule 13G filed with the Securities and Exchange Commission by the Reporting Persons with respect to the Common Stock of the Issuer on January 4, 2022 and Amendment No. 1 thereto filed on January 25, 2024. The items included in this Amendment No. 2 are hereby amended and restated. Y The information required by this item is set forth in the cover pages to this Schedule 13G/A and is incorporated herein by reference. The information required by this item is set forth in the cover pages to this Schedule 13G/A and is incorporated herein by reference. Percentage ownership is based on 2,533,744 shares of Common Stock outstanding as of December 20, 2024, as reported in the Issuer's Report on Form 8-K filed with the Securities and Exchange Commission on December 23, 2024. The information required by this item is set forth in the cover pages to this Schedule 13G/A and is incorporated herein by reference. The information required by this item is set forth in the cover pages to this Schedule 13G/A and is incorporated herein by reference. The information required by this item is set forth in the cover pages to this Schedule 13G/A and is incorporated herein by reference. The information required by this item is set forth in the cover pages to this Schedule 13G/A and is incorporated herein by reference. N Y Y Y Y Y Y Domain Partners IX, L.P. /s/ Lisa A. Kraeutler 01/16/2025 Domain Associates, LLC /s/ Lisa A. Kraeutler 01/16/2025