Metaphase (cell cycle): The stage in the cell cycle (the sequence of events in the life of a cell) when a chromosome is most highly condensed (and stains most darkly in the laboratory) and so is easiest to distinguish and to study.
Metaphase chromosomes are therefore often chosen for karyotyping and for chromosome analysis because they are readily seen. However, chromosomes in metaphase can be so condensed and scrunched up that it is difficult to make out much in the way of detail. More distended chromosomes (in prometaphase or prophase) are sometimes selected for study when fine details are important.
The term "metaphase " was introduced by Strasburger in 1884 to denote the stage in nuclear division after (in Greek: meta) the time when he mistakenly thought chromosomes had just divided into chromatids. It was later realized that chromosomes are already double when nuclear division begins. However, the term "metaphase" has stuck.