FIGURE 6.

Quantification of A2E in mouse eyes. Analyses were done with a synthetic A2E standard and HPLC coupled to MS. A, chromatographic separation of organic compounds extracted from the eyes of 6-month-old Mertk^−/−Abca4^−/−Rdh8^−/− mice (green trace). The peak corresponding to A2E was identified based on its retention time (blue trace), molecular mass (inset), and MS² fragmentation pattern (B), all of which were identical to an A2E synthetic standard. C, amounts of A2E in the eyes of Mertk^−/−Abca4^−/−Rdh8^−/− (TKO), Abca4^−/−Rdh8^−/− (DKO), Mertk^−/−, and WT mice at 1–3 and 6 months of age were quantified by HPLC. Bars indicate S.D. n ≥ 3 animals. D, neural retina was isolated from the eyes of 6-month-old Mertk^−/−Abca4^−/−Rdh8^−/− mice, and A2E quantification of the neural retina and the remaining eyecup was carried out. Bars indicate S.D. n ≥ 3 animals. mAU, milliabsorbance unit.