• The collagen hybridizing peptide (CHP) is a novel and unique peptide that specifically binds unfolded collagen chains, bothin vitroand in vivo.[1,2,3] By sharing the Gly-X-Y repeating sequence of natural collagen, CHP has a strong capability to hybridize with denatured collagen chains by reforming the triple helical structure, in a fashion similar to DNA fragments annealing to complementary DNA strands. CHP is extremely specific: it has negligible affinity to intact collagen molecules due to lack of binding sites, and it is inert towards non-specific binding because of its neutral and hydrophilic nature.
• CHP is a powerful histopathology tool which enables straightforward detection of inflammation and tissue damage caused by a large variety of diseases, as well as tissue remodeling during development and aging.[3]CHP robustly visualizes the total collagen content of tissue sections that have undergone heat-induced epitope retrieval (HIER). The ratio between damaged collagen and total collagen can be a useful metric for evaluating disease/damage progression over time. Additionally, the signal can be quantified using image analysis software including ImageJ for fluorescent quantification (See Application Note)
• The Auto B-CHP incorporates our newest sequence which allows them to be used with automated staining platforms that are “Open” such as the Bond-RXm (Leica), Discovery Ultra (Roche), and Valent (Biocare Medical) systems. The new sequence will not refold over the course of tissue staining and they do not require a pre-activation heating step. The Auto B-CHP is a powerful histology tool which enables straightforward detection of inflammation and tissue damage caused by a large variety of diseases, as well as tissue remodeling during development and aging. [3] The compatibility with numerous “Open” automated staining platforms enables easy, consistent, and reproducible staining that can be done simultaneously with other stains.
• Auto B-CHP is labeled with biotin for avidin/streptavidin-mediated detection. The biotin label offers flexible detection options, such as non-fluorescence and HRP-enzyme methods, to avoid background and enhance signal.
• Specificity:CHP binds to the unfolded triple-helical chains of all collagen types(e.g., I, II, III, IV, etc).[3,7]

Specification

Unheated Tissue- Active Remodeling Collagen

Heated Tissue- Total Collagen

Fibrotic mouse liver sections (FFPE) stained with Auto-CHP. These sections were taken from mice induced with the carbon tetrachloride (CCl4) fibrosis model.  Sections were deparaffinized following a standard protocol and stained on an automated Leica Bond-RXm platform using the Auto-CHP which contains a biotin label. The damaged or remodeling collagen is stained brown with the use of a streptavidin- diaminobenzidine (DAB). The unheated section (left) shows the active remodeling (damaged) collagen present in the tissue due to the progression of fibrosis; dark brown areas indicate regions with high collagen turnover. The heated section (right) had all the collagen in the sample purposefully denatured prior to staining with Auto-CHP. This represents the total amount of collagen present in the serial section. The ratio between total and damaged collagen may offer insight into disease progression.

Features

• New sequence designed for use on automated platforms does not require any pre-activation (pre-heating) step unlike CHPs for manual histology
• Biotin label offers flexibility for imaging numerous fluorescent wavelengths or non-fluorescent imaging with HRP for signal amplification
• Can be used on “Open” systems such as the Bond-RX or RXm (Leica), Valent or IntelliPATH FLX (Biocare Medical), Discovery Ultra (Roche), Autostainer 480S (ThermoFisher), or AS Link 48 (Dako/Agilent)
• High affinity and unparalleled specificity to collagen turnover with essentially no nonspecific binding
• Applicable to all types of collagen from all species, relying on collagen's secondary structure instead of any defined sequence for binding
• Stable in solution under 4 °C for months, eliminating the need to aliquot for storage