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VitroView Picro-Sirius Red Stain Kit (#VB-3017)



Specific staining by Picro-sirius red is one of the most important stains to study collagen networks in different tissues. VitroView™ Picro-Sirius Red Stain Kit is designed for stain of collagen I and III fibers. The Sirius Red stain may be viewed using standard light microscopy or polarized light resulting in birefringence of the collagen fibers to distinguish between type I and type III.


Kit Components

  • VB-3017-1   Weigert’s Hematoxylin Solution A——–125 ml
  • VB-3017-2   Weigert’s Hematoxylin Solution B ——-125 ml
  • VB-3017-3   Picro-sirius Red Solution———————-250 ml
  • VB-3017-4   Acidified Watetr————————————250 ml


Storage Condition

Room temperature.



  •  a).For FFPE slides: Deparaffinize in Xylene I for 6 minutes and II for 6 minutes. Rehydrate: ethanol 100% (2 minutes)×2; ethanol 95% (2 minutes)×2; ethanol 70% (2 minutes)×1;  b). For Frozen Sections: fix frozen sections in 10% formalin for 30 minutes.
  • Rinses in distilled water 2min×3.
  • Prepare Weigert’s working hematoxylin: mix Weigert’s Hematoxylin Solution A and B at 1:1 ratio.
  • Stain nuclei with Weigert’s haematoxylin for 8 minutes, and then wash the slides for 10 minutes in running tap water.
  • Stain in Picro-sirius Red Solution for 1 hour. Note: This gives near-equilibrium staining, which does not increase with longer times. Shorter times should not be used, even if the colors look good.
  • Wash in two changes of acidified water.
  • Wash slides, 2min × 2 in dH2O.
  • Dehydrate with 2 changes of 95% Ethanol and 2 changes of 100% Ethanol (2 minute per change).
  • Clear with 3 changes of xylene (5 minute per change) and coverslip with Permount or other suitable organic mounting medium.


Expected results

Light Microscopy

  • Collagen ————————————————————– red
  • Muscle Fibers —————————————————– yellow
  • Cytoplasm ———————————————————- yellow


Polarized Light Microscopy

  • Type I (Thick fibers) —————————————- yellow‐orange
  • birefringence Type III (Thin fibers) ——————- green birefringence

VitroView Picro-Sirius Red Stain Kit (#VB-3017)

SKU: VB-3017
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