The invention relates to the technical field of molecular biologics, and discloses a PCR-free sequencing
library preparation method for
genome DNA. The PCR-free sequencing
library preparation method comprises the following steps: (1) breaking
genome DNA with ultrasonic
waves; (2) purifying and recycling
DNA fragments; (3) repairing
tail ends of the fragmented DNA; (4) purifying and recycling
tail end repairing products; (5) adding A to the
tail ends of DNA; (6) purifying and recycling the tail end A-added product; (7) adding sequencing connectors on two sides of DNA so as to implement connection reaction; (8) performing fragment screening on connection products, and recycling products, so as to obtain a sequencing
library; (9) performing quality inspection and loading sequencing on the library. The invention provides a
genome DNA ultrasonic breaking method used in the step (1), methods for purifying the products in the steps (2, 4 and 6), reaction systems and conditions in the steps (3, 5 and 7), and design and use methods of the sequencing connectors which are compatible with an Illumina secondary sequencing instrument in the step (7), so that the PCR-free sequencing
library preparation method disclosed by the invention can be rapidly and smoothly implemented, and the loading sequencing library can be directly prepared without PCR reaction (PCR-free) according to the preparation method.