▁that ▁allows ▁for ▁the ▁investigation ▁of ▁phen ot ypes ▁at ▁the ▁level ▁of ▁the ▁trans cript ome , ▁to ▁el uc id ate ▁gene ▁functions ▁in ▁many ▁cells , ▁in ▁a ▁mass ively ▁parallel ▁fashion . ▁ ▁The ▁P ert urb - seq ▁protocol ▁uses ▁CR IS PR ▁technology ▁to ▁in activ ate ▁specific ▁gen es ▁and ▁DNA ▁bar c oding ▁of ▁each ▁guide ▁R NA ▁to ▁allow ▁for ▁all ▁perturb ations ▁to ▁be ▁po o led ▁together ▁and ▁later ▁de con vol uted , ▁with ▁assignment ▁of ▁each ▁phen ot ype ▁to ▁a ▁specific ▁guide ▁R NA . ▁Dro ple t - based ▁micro fl uid ics ▁platforms ▁( or ▁other ▁cell ▁sorting ▁and ▁separ ating ▁techniques ) ▁are ▁used ▁to ▁isol ate ▁individual ▁cells , ▁and ▁then ▁sc R NA - seq ▁is ▁performed ▁to ▁generate ▁gene ▁expression ▁profiles ▁for ▁each ▁cell . ▁Upon ▁completion ▁of ▁the ▁protocol , ▁bio in format ics ▁anal ys es ▁are ▁conducted ▁to ▁associate ▁each ▁specific ▁cell ▁and ▁perturb ation ▁with ▁a ▁trans cript omic ▁profile ▁that ▁character izes ▁the ▁consequences ▁of ▁in activ ating ▁each ▁gene . ▁ ▁In ▁the ▁December ▁ 2 0 1 6 ▁issue ▁of ▁the ▁Cell ▁journal , ▁two ▁companion ▁papers ▁were ▁published ▁that ▁each ▁introduced ▁and ▁described ▁this ▁technique . ▁A ▁third ▁paper ▁describing ▁a ▁concept ually ▁similar ▁approach ▁( ter med ▁CR IS P - seq ) ▁was ▁also ▁published ▁in ▁the ▁same ▁issue . ▁In ▁October ▁ 2 0 1 6 , ▁the ▁C ROP - seq