 In most LSFMs the detection objective and sometimes also the excitation objective are fully immersed in the sample buffer, so usually the sample and excitation/detection optics are embedded into a buffer-filled sample chamber, which can also be used to control the environmental conditions (temperature, carbon dioxide level ...) during the measurement.The sample mounting in LSFM is described below in more detail.As both the excitation lightsheet and the focal plane of the detection optics have to coincide to form an image, focusing different parts of the sample can not be done by translating the detection objective, but usually the whole sample is translated and rotated instead.