Labeled carcinoembryonic antigen antibodies excitable by infrared rays: a novel diagnostic method for micro cancers in the digestive tract.
OBJECTIVE
An indocyanine green derivative (ICG-sulfo-OSu) was used as the labeling substance for monoclonal antibody, and a fluorescence imaging system appropriate for ICG-sulfo-OSu excitable by infrared rays (IR) was developed. The goal of this study was to demonstrate antibody labeling at the tissue level using this new imaging system.


METHODS
ICG-sulfo-OSu labeled mouse anti-human carcinoembryonic antigen (CEA) monoclonal antibody, a newly developed imaging system, and an infrared ray microscope were employed in this experiment. Paraffin sections of human colon cancer previously proven to have cross-reactivity to anti-CEA antibody were examined.


RESULTS
Positive staining was seen as a brownish discoloration of oxidized 3,3'-diaminobenzidine tetrahydrochloride (DAB) in sections that reacted with ICG-sulfo-OSu-labeled anti-CEA antibody, and the fluorescence was well-matched with the oxidized DAB-positive sites.


CONCLUSIONS
Specific antibodies labeled with ICG-sulfo-OSu have significant affinity to cancer cells and seem to reflect sufficient amounts of fluorescence by IR to be useful in a system for the endoscopic detection of micro cancers using the immunohistochemical staining method.
Muguruma
N
N
Second Department of Internal Medicine, The University of Tokushima.
Ito
S
S
Bando
T
T
Taoka
S
S
Kusaka
Y
Y
Hayashi
S
S
Ichikawa
S
S
Matsunaga
Y
Y
Tada
Y
Y
Okamura
S
S
Ii
K
K
Imaizumi
K
K
Nakamura
K
K
Takesako
K
K
Shibamura
S
S
D000230:Adenocarcinoma / Q000175:diagnosis / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen / Q000378:metabolism; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000276:immunology; D003429:Cross Reactions; D005456:Fluorescent Dyes; D006801:Humans; D007150:Immunohistochemistry; D007208:Indocyanine Green / Q000031:analogs & derivatives; D007259:Infrared Rays; D051379:Mice; D008856:Microscopy, Fluorescence / Q000295:instrumentation; D016612:Paraffin Embedding
D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D005456:Fluorescent Dyes; C113792:indocyanine green-sulfo-OSu; D007208:Indocyanine Green