actin a major protein constituent of the thin filaments of muscle and of the microfilaments found in practically all eukaryotic cells – it comprises 5–10% of the protein of such cells (see actin filament). In solutions of low ionic strength, actin is a globular 42 kDa monomer, termed G-actin. At physiological ionic strengths, G-actin polymerizes
acridinium esters: esters of acridine-9-carboxylic acid. They have a quaternary nitrogen centre and are derivatized at the 9 position to give a labile phenyl ester moiety. Acridinium esters such as 2′,6′-dimethyl-4′-[N-succinimidyloxy carbonyl]phenyl-10-methylacridinium- 9-carboxylate can be used as chemiluminescent labels for antibodies. Light emission is activated by adding hydrogen peroxide under alkaline conditions. In hybridization protection
صبغ يتميز بالألفة تجاه الحموض النووية. فمعقد الحمض النووي مع الصبغ يشع اللون البرتقالي عند ارتباطه ب RNA و بالأخضر مع DNA و ذلك عند رؤيته بالمجهر الفلورنسي . الصيغة الكيميائية لهذه المادة C17H19N3 و وزنها الجزيئي 265.35 .