Sometimes pathologists are not able to determine the diagnosis based on the frozen section and instead must rely on the permanent section. In this procedure the tissue is not frozen but instead is placed in a fixative solution, embedded in wax, thinly cut, and then stained. Although this takes longer than a frozen section (usually 1 day), the permanent section leads to better-quality microscope slides. All biopsies are limited by the sample taken. Cancer or other diseases may be so small that they are not present in the tissue sample but may still be present elsewhere. Multiple biopsies may be needed to make a diagnosis.