Technical Information on Fluorochrome Antibody Conjugates

Affinity purified antibodies labelled with fluorochromes are time-proven markers of tissue and plasma membrane antigens. For purposes of immunocytological investigations, PROTOS IMMUNORESEARCH provides antibody conjugates of fluorescein (FITC), rhodamine (TMRITC) and Texas Red. These can be used as individual reagents or in double antibody experiments in fluorescence microscopy, flow cytometry and fluorometric immunoassays. Combinations of FITC and Texas Red conjugates are well suited for flow cytometry, because their emission spectra are widely separated (i.e., 515 nm vs 615 nm).

Antibody studies of cells and tissues that have Fc-receptors often are complicated by non-specific reactions, which are greatly diminished if the Fc part of antibodies is removed to produce F(ab')2 fragments. PROTOS IMMUNORESEARCH prepares antibody F(ab')2 fragments both as unconjugated and conjugated reagents for immunocytological and tissue investigations.

In addition,  FITC conjugated Fab' fragments of affinity purified antibodies are provided for studies where increased tissue or cellular penetration are important. The Fab' (i.e.3.5S) fragments are monovalent (non-crosslinking).

Depending upon the technology employed, the usual working dilutions for fluorochrome conjugates are >1:50 and <1:300.

Indicator : antibody ratios are as follows:

FITC conjugates,  Mol.F/P ratios-whole Abs :4-6

                                              F(ab')2 fragments :3-5

                                              Fab' fragments :1.5-2.5

          Rhodamine conjugates OD515/OD280 :0.5-0.8

           Texas Red conjugates OD596/OD280 :0.6-1.0

Protos Immunoresearch
875A Cowan Road, Burlingame, CA 94010
Tel: 650 652-3450      Fax: 650 652-3451

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