Independent Uniform Random (IUR) sections
IUR sections, also known as isotropic or random sections, are important to stereologists, less so to biologists. They are used by many estimators including the nucleator, planar rotator, optical rotator, length estimation by counting intercepts, and the surfactor. IUR sections are more random than vertical sections and therefore can be used as vertical sections with cycloids for estimation of length and surface.
There are two well known methods for creating IUR sections from tissue, the isector and the orientator. The isector is better for small tissue samples, while the orientator is better for larger pieces of tissue.
A method of creating random sections while following an atlas has been described by Dorph-Peterson. This paper describes the detailed laboratory procedures that combine preferential cutting of an organ with the final preparation of random sections. The preferential cutting of the brains was necessary to follow an atlas to the portion of the brain that was being investigated. Once the proper portion of the brain was located, random sections were produced. The sections created were VUR sections, but the same steps can lead to the creation of IUR sections.