Fig. 1

Lymph node processing for OSNA pooling and individual analysis. First two steps (a, b) are common for both cohorts. a Lymph nodes freshly dissected from the mesocolon fat are cut in half; b a 1 mm central slice is put in a cassette and used for FFPE and H&E analysis. The rest of the lymph node is put into a microcentrifuge tube for ulterior OSNA analysis; c Individual OSNA analysis: After the process of a, b, each central lymph node slice is individually put in a cassette for FFPE and H&E analysis. The rest of the lymph node is put into a microcentrifuge tube for individual OSNA analysis. d Pooling analysis: Lymph nodes are identically processed and put together into a microcentrifuge tube and a cassette for OSNA and H&E analysis, respectively. e Microcentrifuge tube containing multiple lymph nodes (pool) for simultaneous OSNA analysis