Starkey JR, Makarov NS, Drobizhev M, Rebane A.
Biomed Opt Express. 2012 Jul 1;3(7):1534-47. doi: 10.1364/BOE.3.001534. Epub 2012 Jun 6.We describe novel imaging protocols that allow detection of small cancer cell colonies deep inside tissue phantoms with high sensitivity and specificity. We compare fluorescence excited in Styryl-9M molecules by femtosecond pulses at near IR wavelengths, where Styryl-9M shows the largest dependence of the two-photon absorption (2PA) cross section on the local environment. We show that by calculating the normalized ratio of the two-photon excited fluorescence (2PEF) intensity at 1200 nm and 1100 nm excitation wavelengths we can achieve high sensitivity and specificity for determining the location of cancer cells surrounded by normal cells. Read More