Fig. 2
ssDNA library enrichment. a Positive enrichment steps towards a library that identifies non-benefitting (NB) cases: (i) incubation of the ssDNA library with the NB tissue; (ii) removal of unbound sequences, (iii) dissection of tumour tissue and recovery of the subset of sequences, specific to the NB cancer tissue. SN, supernatant. Recovered ssDNAs were amplified by PCR, converted to ssDNAs and used for the next enrichment round. Slide images on the left show tissue appearance: Slide (1) Haematoxylin and eosin (H&E) staining of NB tissue (tumour area outlined in green); Slide (2) Nuclear Fast Red (NFR)-stained tissue after library partitioning before dissection; Slide (3) Remaining normal tissue after dissection of cancer tissue with bound ssDNAs. b Enrichment steps with additional counter-selection steps on benefit (B) cases: (i) incubation of the ssDNA library with the first B tissue; (ii) incubation of the supernatant from (i) with the second B case; (iii) incubation of the supernatant from (ii) with the NB case from a; (iv) and (v) correspond to the steps (ii) and (iii) in a, respectively. Slide images on the left show tissue appearance: Slide (4) H&E staining of first B tissue (tumour area outlined in green); Slide (5) H&E staining of second B tissue (tumour area outlined in green); Slides 2 and 3 are same as in a. c The entire ssDNA library enrichment is comprised of three enrichment rounds as shown in a, followed by three enrichment rounds as shown in b
