Abstract: A method, system and device for programmed cell freezing is disclosed. The method includes: S1, acquiring a cooling rate k and a temperature distribution function T=a×h2+b×h+c of a heat preservation chamber containing liquid nitrogen; S2, controlling a cell preservation tube to lower in the chamber at a speed of v=(k-b)/2ah, and acquiring temperatures T1 and T2 inside and outside the tube at a same time and at a same height in real time during the lowering of the tube; S3, determining whether a difference ?t between T1 and T2 exceeds a preset temperature difference threshold, if yes, proceeding to S4, and if no, proceeding to S2 until the tube reaches a position corresponding to a preset temperature T0; and S4, controlling the cell preservation tube to stop until the difference ?t between T1 and T2 is less than or equal to the temperature difference threshold, and continuing S2.

Abstract: The present application discloses a primer set, a reagent, a kit for detecting methylation of a specific region of a human colorectal cancer-related gene from feces, blood, or tissue by using specific PCR, and the application thereof. The primer set includes specific amplified primer probe sequences for the methylated regions of specific regions of the gene markers PRDM12, FOXE1, and B3GAT2 genes found in this study; and the primer probe group also includes the specific amplification primer probe sequence of the methylated region of the specific region of the Vimentin, SFRP2-1, and SFRP2-2 genes and the specific amplification primer probe group of the internal reference gene ACTB, thus having high detection efficiency and strong pertinence.