Carrier-Free antibodies are formulated in PBS without BSA or Azide.
Additives can protect antibodies, but also decrease their utility in some applications.
Most commercially available antibodies are supplied in a buffer such as PBS or Tris/NaCl and include stabilizers like bovine serum albumin (BSA), sodium azide, and glycerol. These additives prevent contamination, preserve antibodies, and maintain stability. While they generally do not interfere with techniques like IHC, ICC, ELISA, or Western blot, they can hinder conjugation to fluorophores, metals, and enzymes.
Carrier-free antibodies provide researchers with greater flexibility, enabling precise customization of antibody conjugates and buffer compositions to suit specific assay requirements.
There are several potential advantages to carrier-free antibodies, including increased sensitivity, lower background, and versatility.
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Improved Sensitivity:
Carrier proteins like BSA help stabilize antibodies but can compete for conjugation sites, potentially reducing labeling efficiency. This can lower assay sensitivity, particularly when detecting low-abundance proteins, where maximizing signal strength is critical.
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Lower Background and Cross Reactivity:
BSA (bovine serum albumin) is a biological reagent can non-specifically bind to some primary or secondary antibodies. Carrier free antibodies reduce this type of interference, resulting in a cleaner signal and lower background.
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Suitability for Conjugation:
Sodium azide preserves antibodies but is toxic to cells and disrupts labeling. For bioconjugation applications such as the attachment of fluorophores or enzymes, these components must be removed. Carrier-free antibodies allow researchers to more easily conjugate the antibody to a variety of labels.
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Multiplexing Enhancement:
Carrier-free antibodies are especially relevant in multiplexing, mass cytometry, and flow cytometry, where antibodies must be conjugated to distinct fluorophores, metals, or enzymes without interference. In these applications, precise and efficient labeling is critical for distinguishing multiple targets within the same sample. Carrier proteins like BSA can compete for conjugation sites, and preservatives like sodium azide can disrupt labeling chemistry.