| CAS #: 1334172-58-5 Amount: 1000 mg  
Item Name: Biotin-dPEG®4-PFP ester Item #: 10010 Mol. Wt.: 657.65; single compound dPEG® Spacer is 16 atoms and 19.2 A Product Features and Benefits: Amine reactive pegylation biotinylation reagent with a dPEG®4 spacer arm Optimal for solid phase synthesis, as alternative to the NHS ester (10200) Very water soluble, hydrophilic and eliminates non-specific binding upon labeling. Ideal spacer length for binding streptavidin conjugates; chain length from amide to terminal carbonyl is 19.2 Angstroms. Designed to be the same length as the LC-LC spacer, which is considered an ideal length for the streptavidin binding pocket. Non-antigenic and non-immunogenic spacer arm Application: ELIMINATES aggregation and precipitation when labeling antibodies and other biological materials (a severe problem with conventional biotinylation reagents) Protocol: See Hermanson (reference), pg. 728 for the NHS-dPEG®4 biotin. While the NHS ester can be used directly in water, this should, as the protocol calls, be dissolved in an organic solvent for optimal and easiest application. Reference: Greg T. Hermanson, Bioconjugate Techniques, 2nd Ed, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds. | 
