Not necessary. In major cases tips are the cause of bad results in terms of precision. A poor quality or a non-low retention tip can result in exceeding the allowed margin of imprecision, specified on the conformity certificate delivered with each pipette. Capp recommends to use ExpellPlus low retention tips in order to obtain the best pipetting results. ExpellPlus low retention tips are specially polished inside and tend to retain much less volume than the majority of commonly used pipette tips. Write at to order a free sample package of ExpellPlus low retention tips.