Abstract
Telomere repeats at chromosomal ends are essential for genome stability and sustained cellular proliferation but are susceptible to DNA damage. Repair of damage at telomeres is influenced by numerous factors including telomeric binding proteins, sequence and structure. Ultraviolet (UV) light irradiation induces DNA photoproducts at telomeres that can interfere with telomere maintenance. Here we describe a highly sensitive method for quantifying the formation and removal of UV photoproducts in telomeres isolated from UV irradiated cultured human cells. Damage is detected by immunospot blotting of telomeres with highly specific antibodies against UV photoproducts. This method is adaptable for measuring other types of DNA damage at telomeres as well.