Colcemid, also known as demecolcine, is a synthetic
analog of colchicine. It is less toxic to cells than
colchicine. Being a mitotic inbitor, colcemid binds to the
tubulin protein and obstructs the spindle fibre formation.
At very low concentration it binds to microtubule plus
end and affects the microubule dynamics by causing
depolymerisation. It effectively arrests cell in metaphase,
allowing cell harvest and karyotyping to be performed.
Colcemid is used to arrest different types of cells in
metaphase like peripheral blood cells, amniotic fluid
cells, fibroblasts, bone marrow cells and cells from
chorion villus samples, etc. Exposure of cells to colcemid
depends upon quantity of colcemid and the type of cell.
A longer exposure will result in more metaphases but
with shorter chromosomes. Longer chromosomes are
generally preferred for cytogenetic studies.
TCL074 is a sterile filtered solution of 10µg per ml of
Colcemid is Hank's balanced salt solution.