S-phase index (SPI), is a measure of

cell growth Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a de ...

and viability, especially the capacity of tumor cells to proliferate.'' Oncology Nursing Forum'', Volume 18, p. xxv (Oncology Nursing Society, 1991). It is defined as the number of

BrdU Bromodeoxyuridine (5-bromo-2'-deoxyuridine, BrdU, BUdR, BrdUrd, broxuridine) is a synthetic nucleoside analogue with a chemical structure similar to thymidine. BrdU is commonly used to study cell proliferation in living tissues and has been s ...

-incorporating cells relative to the volume of

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

staining Staining is a technique used to enhance contrast in samples, generally at the Microscope, microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissue (biology), tissues), in cytology (microscopic ...

determined from whole mount confocal analyses. Only cells in the

S phase S phase (Synthesis phase) is the phase of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Since accurate duplication of the genome is critical to successful cell division, the processes that occur during S ...

will incorporate BrdU into their DNA structure, which assists in determining length of the

cell cycle The cell cycle, or cell-division cycle, is the sequential series of events that take place in a cell (biology), cell that causes it to divide into two daughter cells. These events include the growth of the cell, duplication of its DNA (DNA re ...

References

* Murphy, Terence D. "''Drosophila skpA, a component of SCF ubiquitin ligases, regulates centrosome duplication independently of cyclin E accumulation''", ''

Journal of Cell Science The ''Journal of Cell Science'' (formerly the ''Quarterly Journal of Microscopical Science'') is a peer-reviewed scientific journal in the field of cell biology. The journal is published by The Company of Biologists. The journal is partnered with P ...

'' 116, 2321-2332 (2003). Cellular processes {{Cell-biology-stub