Cov tshuaj reagent yog cov khoom siv txheeb ze rau kev tshawb fawb tshuaj thiab kev tshuaj ntsuam xyuas, thiab yog ib qho tseem ceeb rau kev tshawb fawb thiab thev naus laus zis, uas yog siv dav hauv kev sib xyaw, kev sib cais, kev soj ntsuam zoo thiab ntau yam ntawm cov khoom.