Send to

Choose Destination
See comment in PubMed Commons below

Alexa 680 conjugated to bovine serum albumin.


Chopra A.


Molecular Imaging and Contrast Agent Database (MICAD) [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 2004-2013.
2012 Mar 08 [updated 2012 Mar 29].


The lymphatic system collects lymph, the excess protein-rich fluid that diffuses out of blood vessels, and returns it to blood circulation (1). The flow of lymph in the system is unidirectional, and in addition to proteins it carries various antigens and antigen-presenting cells (activated) to the lymph nodes, which is where the effector cell and humoral immune responses are launched into the circulatory system (for details, see Alitalo (1)). A damaged lymphatic system (due to hereditary or accidental reasons) can lead to the development of a suboptimal immune response and/or lymphedema due to the accumulation of lymph, fat, and connective tissues at the affected site. There is currently no effective treatment for lymphedema (2). In addition, the functioning of the lymphatic system and the process of lymph flow are not well understood because there is a lack of suitable invasive or noninvasive method(s) (such as imaging) that can be used for the preclinical or clinical study of these physiological processes (1, 2). Quantitative lymphoscintigraphy is commonly used to visualize lymphatic function and lymph flow in animals and humans; however, the main disadvantages of using this method are the application of radioactive materials, limited spatial resolution of the images, and the possibility of direct radionuclide diffusion into the surrounding normal tissues through microcapillaries as a result of proteolysis, dissociation of radiotracer from the imaging agent, and vascular transport (3). Optical imaging has been used to assess the lymphatic functions in mice after direct intradermal injection of indocyanine green (ICG), a small molecule near-infrared fluorescence dye, but quantification of lymph flow in the animals was difficult because the dye was cleared rapidly from the interstitium by the lymphatics and blood circulation in the animals (2, 4). In another study, liposome-enclosed ICG (LP-ICG) was used for the imaging of the mouse lymphatic system, and in the same study the preparation was shown to be unstable in 50% fetal bovine serum (5). This indicated that release of free ICG into the system from the LP-ICG preparation could result in an inaccurate estimation of lymph flow in the animals. In addition, free ICG was reported to alter contractility of the rat lymphatic vessels in a dose- and dilution-dependent manner, suggesting that measurement of lymph flow with ICG may not be a true representation of the process in the animals (6). In a continued effort to develop an agent that can be used with a noninvasive technique to measure the lymph flow in rodents, Alexa 680–labeled bovine serum albumin (Alexa680-BSA) was synthesized and evaluated with near-infrared fluorescence imaging in normal mice and rats and in lymphedema (Chy) mice (2).

PubMed Commons home

PubMed Commons

How to join PubMed Commons
    Support Center