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Fab fragment antibodies are generated by papain digestion of whole IgG antibodies to remove the entire Fc portion, including the hinge region. These antibodies are monovalent, containing only a single antigen binding site. The molecular weight of Fab fragments is about 50 kDa.
Storage and Rehydration: Store freeze-dried solid at 2-8°C. Rehydrate with the indicated volume of dH2O (see product specification sheet) and centrifuge if not clear. Prepare working dilution on day of use. Product is stable for about 6 weeks at 2-8°C as an undiluted liquid.
Extended Storage after Rehydration: Aliquot and freeze at -70°C or below. Avoid repeated freezing and thawing. Alternatively, add an equal volume of glycerol (ACS grade or better) for a final concentration of 50%, and store at -20°C as a liquid.
Expiration date: one year from date of rehydration. The expiration date may be extended if test results are acceptable for the intended use.
1:100 - 1:800 for sequential labeling applications.
To complex with primary antibody in solution, use 1:1 weight ratio of Fab:primary antibody (15:1 molar ratio). Vortex and incubate for 30 minutes at room temperature prior to use. Titrate complex to optimal dilution for assay.
Dilution factors are presented in the form of a range because the optimal dilution is a function of many factors, such as antigen density, permeability, etc. The actual dilution used must be determined empirically.
DyLight 405-conjugated secondary antibodies are excited maximally at about 400 nm and fluoresce with a peak at about 421 nm. They are very bright and photostable, but their optimal use is limited to microscopes or flow cytometers equipped with a 405 nm laser and a 420 nm emission filter. Under these conditions, it is possible to perform effective 4-color imaging with good color separation, good photostability, and high sensitivity. The combination of DyLight 405, Alexa Fluor® 488, Rhodamine Red-X, and Alexa Fluor® 647 provides for maximum color separation. Another 4-color dye combination, which may be equally effective but has slightly less color separation, is DyLight 405, Alexa Fluor® 488, Cy3, and Alexa Fluor® 647. DyLight 405 conjugates are an excellent choice for blue-fluorescing secondary antibodies in multi-color labeling protocols.
This product is for in vitro research use only. It is not a medical device and it is not intended for diagnostic or therapeutic purposes.
DyLight™ is a trademark of Thermo Fisher Scientific, Inc. and its subsidiaries.