Toxin Analysis is a common Instant card from Murders at Karlov Manor (MKM), collector number 107. Current market price: $0.24 (foil $0.24), TCGplayer market prices via Scryfall.
Target creature gains deathtouch and lifelink until end of turn. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")