Animal tissue sampling is an important step in pathological staining or molecular detection experiments. The collected animal tissues can be paraffin embedded, sectioned and stained after effective fixation. Now we will introduce cardiac tissue sampling, selection of sectioning direction and common pathological special staining.

Figure 1. Sample embedding orientations (a) and (b) and thephotos of the last scanned sections of the rat hearts embeddedin the way. (Xu HN, et al.; 2014)

Heart tissue sampling, the process of obtaining small samples of heart tissue for analysis, has evolved considerably in recent years. Traditional methods often involved invasive procedures that carried risks for the patient. However, with advancements in minimally invasive techniques, such as cardiac catheterization and endomyocardial biopsy, obtaining heart tissue samples has become safer and more accessible. These techniques allow clinicians to collect tissue samples directly from the heart with minimal discomfort to the patient, reducing the need for more invasive surgical procedures.

Embedding Section Direction

Transection of the base of the heart and lower part of the atrial appendage - observation of the aortic valve and aortic sinus

Transect the apex of the heart - observe the left and right ventricles

Parallel longitudinal section of the auricle - observe the four chambers: left and right atria and left and right ventricles

Special Staining of the Heart

• HE Staining

a. Purpose and application of staining-observation of myocardial histopathological changes

b. Histopathological description - the infarct area is loose and edematous, the capillaries are dilated, and inflammatory cells are infiltrated. Further development of necrotic muscle fibers is replaced by loose fibrous connective tissue. Surviving cardiomyocytes scattered around the edge of the infarction are hypertrophic and fibroblast hyperplasia. Large area of collagen fiber deposition, mainly type I and III collagen fibers, resulting in fibrous scar formation

c. Specimen preparation method-4% paraformaldehyde fixed paraffin embedded section

• WGA Malt Agglutinin Fluorescence Staining

a. Purpose and application of staining-observation of myocardial cell membrane integrity

b. Histopathological description - myocardial cell membrane shows bright green fluorescence

c. Specimen preparation method-4% paraformaldehyde fixed paraffin embedded section

• Masson Stain

a. Purpose and application of staining-observation of myocardial collagen fiber deposition

b. Histopathological description-collagen fibers blue, myocardium red

c. Specimen preparation method-4% paraformaldehyde fixed paraffin embedded section

• Sirius Red Staining

a. Purpose and application of staining-observation of myocardial collagen fiber deposition

b. Histopathological description - under a white light microscope, collagen fibers are red and myocardium is yellow; under a polarized light microscope, type I collagen is red and yellow, and type III collagen is green.

c. Specimen preparation method-4% paraformaldehyde fixed paraffin embedded section

• Prussian Blue Staining

a. Purpose and application of staining-observation of iron deposition in myocardial tissue

b. Histopathological description - iron ion-rich areas are blue and cell nuclei are red.

c. Specimen preparation method-4% paraformaldehyde fixed paraffin embedded section

• TTC Staining

a. Purpose and application of staining-observation of myocardial infarction and measurement of infarct area

b. Histopathological description-the infarcted area is pale and the normal area is red.

c. Specimen preparation method - fresh tissue or -80℃ frozen tissue cut into 2mm tissue for staining

Conclusion

In conclusion, the progress of heart tissue sampling, embedding orientation, and staining has significantly advanced our ability to analyze heart tissue with precision and accuracy. From minimally invasive sampling techniques to automated embedding systems and advanced staining methods, these innovations have transformed the field of cardiac pathology. As technology continues to evolve and new discoveries are made, the future of heart tissue analysis holds great promise for improving diagnosis, treatment, and patient outcomes in cardiac diseases.

Related Products

1. Xu HN, et al.; 3D IMAGING OF THE MITOCHONDRIAL REDOX STATE OF RAT HEARTS UNDER NORMAL AND FASTING CONDITIONS. J Innov Opt Health Sci. 2014, 7(2):1350045.

*If your organization requires the signing of a confidentiality agreement, please contact us by email.

Please note: Our services can only be used for research purposes. Do not use in diagnostic or therapeutic procedures!