In most labs where pipetting operations are regularly conducted, certain analysis and operations involve challenging liquids. These liquids may be viscous, light-sensitive, or possess fluorescent properties. It is also likely that the operations may involve handling of fluids under strict conditions or be corrosive or dangerous if it meets skin or other surfaces. In such cases, pipetting becomes a challenge. Nevertheless, it is possible with due care and proper preparation. Tips to pipette fluids of varying density and samples that require high precision results If the density of a liquid is very low, as in the case of PCR reagents, pipetting can be performed efficiently with narrow orifice tips. Along with an extended tip support, the addition of an extra narrow tip will improve the reproducibility of the results. Standard tips of 10uL will work fine with liquids that have densities similar to that of water. In certain lab operations, high precision and reproduc