<prompt> An antibiotic not acting on tubulin isBleomycinColchicinePaclitaxelVincristine  <response>: ANSWER: A BleomycinREF: Goodman Gillman manual of pharmacology and therapeutics 2008 edition various pages, h ttp:e n. wikipe dia. orgwiki Spindle_poisonMitotic spindle poisons:These poisons disrupt cellular reproduction by affecting the protein threads which connect the centromere regions of chromosomes, known as spindles tubulin.MebendazoleColchicineGriesofulvinVinca Alkaloids vincristine, vinblastinePaclitaxel Taxans 