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Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissues ), in cytology (microscopic study of cells ), and in the medical fields of histopathology , hematology , and cytopathology that focus on the study and ...
A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. [1] Contrast agents absorb or alter external electromagnetism or ultrasound , which is different from radiopharmaceuticals , which emit radiation themselves.
Iodinated contrast contains iodine.It is the main type of radiocontrast used for intravenous administration.Iodine has a particular advantage as a contrast agent for radiography because its innermost electron ("k-shell") binding energy is 33.2 keV, similar to the average energy of x-rays used in diagnostic radiography.
Contrast CT of a patient with brain metastases from breast cancer, before (left) and after (right) injection of iodinated contrast.. Iodinated contrast is a form of water-soluble, intravenous radiocontrast agent containing iodine, which enhances the visibility of vascular structures and organs during radiographic procedures.
Phase-contrast microscopy is particularly important in biology. It reveals many cellular structures that are invisible with a bright-field microscope , as exemplified in the figure. These structures were made visible to earlier microscopists by staining , but this required additional preparation and death of the cells.
Nicotinamide adenine dinucleotide phosphate, abbreviated NADP [1] [2] or, in older notation, TPN (triphosphopyridine nucleotide), is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require NADPH as a reducing agent ('hydrogen source').
DOTA is derived from the macrocycle known as cyclen.The four secondary amine groups are modified by replacement of the N-H centers with N-CH 2 CO 2 H groups. The resulting aminopolycarboxylic acid, upon ionization of the carboxylic acid groups, is a high affinity chelating agent for di- and trivalent cations.
A contrast effect is the enhancement or diminishment, relative to normal, of perception, cognition or related performance as a result of successive (immediately previous) or simultaneous exposure to a stimulus of lesser or greater value in the same dimension. (Here, normal perception, cognition or performance is that which would be obtained in ...