Practice question

In vivo transcriptome methods aim to examine RNA within living biological context or preserve spatial and physiological conditions, such as direct RNA sequencing from freshly harvested organisms, FISH performed on fixed but morphologically intact specimens retaining tissue architecture, and CAGE capturing authentic capped transcripts from living material. Microarray technology requires RNA extraction, purification, labeling, and hybridization to synthetic probes on an artificial substrate outside the organism. This intermediate in vitro processing disconnects RNA from native context, making microarray primarily an ex vivo analytic platform rather than direct in vivo observation.