Flow cytometric measurement of telomere length.

The regulation of telomere length may be involved in the cellular physiology of senescence, reproduction, cancer, immune response to infection, and possibly immune deficiency. The measurement of telomere length, critical to research in this area, has traditionally been performed by Southern blot analysis, which is cumbersome and time consuming. Several alternative methods have been described in recent years. Some, such as pulsed-field electrophoresis, slot blots, and centromere-to-telomere ratio measurements are essentially improvements to the Southern blot technique. However, other methods such as fluorescent in situ hybridization on metaphase chromosome spreads and flow cytometry-based fluorescent in situ hybridization represent a completely new technical approach to the problem. In this review, we compare methods, with particular emphasis placed on flow cytometric techniques for measuring telomere length in situ and identifying potential areas where improvements may still be made.