Additional Text

UniProt ID

Q99376

Purification

Purified

Antibody Clonality

Recombinant Monoclonal

Storage Note

Store at 4⁰C for up to 3 months. For longer storage, aliquot and store at -20⁰C.

Short Description

This chimeric human antibody was made using the variable domain sequences of the original Mouse IgG2a format, for improved compatibility with existing reagents, assays and techniques.

Application Notes

The original format of this antibody (mouse IgG2a) was developed and demonstrated to effectively labele transferrin receptor-expressing cells, including dividing lymphocytes and erythroid precursors, with minimal binding to non-dividing lymphoid cells or mature erythrocytes. It was used for fluorescence-based cell sorting to isolate subpopulations of rat hematopoietic stem and progenitor cells from bone marrow and fetal liver (Jefferies et al., 1985; PMID: 2981766). The original format of the antibody was employed in immunohistochemical staining of cryostat sections from rat brain. In vivo testing in PVG/c rats involved injecting the antibody intravenously, followed by cryostat sectioning and staining. The results showed clear labelling of rat brain capillaries, especially in the cerebellum and cortex, with weaker labelling after 16 hours. No such labelling was observed in other rat tissues, supporting the specificity for brain capillaries (Jefferies et al., 1984; PMID: 6095085). This antibody was utilized as a drug carrier to deliver compounds across the blood-brain barrier (BBB) in vivo in Sprague-Dawley rats. The antibody demonstrated selective, dose-dependent binding to brain capillary endothelial cells when administered intravenously, with localization observed as early as 5 minutes post-injection and evidence of transcytosis into the brain parenchyma over time. When conjugated with methotrexate (MTX), the antibody retained its targeting capabilities, facilitating significant accumulation of the drug in the brain parenchyma compared to free MTX (Friden et al., 1991; PMID: 2052557). This antibody was used to deliver nerve growth factor (NGF) across the BBB in in vivo experiments with aged Fischer 344 rats. The OX-26-NGF conjugate was administered intravenously and demonstrated significant therapeutic effects, including enhanced cholinergic markers in grafted tissue, improvement in spatial learning in aged rats, and upregulation of NGF receptors (Granholm et al., 1998; PMID: 9683326). Mutational screening showed that this antibody's crossing of the BBB is dependent on the its affinity to the receptor (Thom et al., 2018; PMID: 29485883). The antibody can also be used in flow cytometry, immunofluorescence, and western blot, and it may also be used in frozen-section IHC.