The centromere is the location of spindle attachment and is an integral part of the chromosome. It is essential for the normal movement and segregation of chromosomes during cell division. Human metaphase chromosomes come in three basic shapes and can be categorized according to the length of the short and long arms and also the centromere location. Metacentric chromosomes have short and long arms of roughly equal length with the centromere in the middle. Submetacentric chromosomes have short and long arms of unequal length with the centromere more towards one end.
Acrocentric chromosomes have a centromere very near to one end and have very small short arms.
They frequently have secondary constrictions on the short arms that connect very small pieces of DNA, called stalks and satellites, to the centromere. The specific banding patterns are also illustrated. Each band is numbered to aid in describing rearrangements. Virtually all routine Cytogenetic analyses are done on chromosome preparations that have been treated and stained to produce a banding pattern specific to each chromosome. This allows for the detection of subtle changes in chromosome structure.