Histosonda®

Most of the thyroid cellular mass is constituted by the thyroid follicular cells that group to form colloid containing follicles.  Colloid is principally made up of a dimeric protein with a molecular weight of 660 kDa.  The tyrosine amino acids of this protein are iodinated and liberated by proteolysis to form thyroid hormones.

HISTOSONDA Thyroglobulin consists of a single stranded, 552 nucleotide fragment of DNA which is complementary to thyroglobulin mRNA and labeled with digoxigenin.

In situ hybridization offers many advantages over immunohistochemistry in that it completely eliminates the intense tissue background that is produced by colloid when using antibodies against thyroglobulin.

INTENDED USE

For use in In Vitro Diagnosis.

The Kit Histosonda Thyroglobulin is useful for the detection of thyroid tumors and their metastases, drawing special attention to those Medullary Carcinomas with a follicular pattern and metastases of papillary tumors that are distinct from thyroid papillary carcinomas.

WARNINGS AND PRECAUTIONS

The Kit Histosonda Thyroglobulin has been designed for professional use in In Vitro Diagnosis and must be manipulated by qualified and accordingly trained personnel.

In order to obtain the best results, the instructions contained in the manual must be followed. Any change to the indicated temperatures, times or any other step of the process can lead to poor results.

KIT COMPONENTS

The Kit includes 20 single test tubes of Histosonda Thyroglobulin; 20 single test tubes of Proteinase K and 2 tubes of Anti-Digoxin antibody sufficient for 20 tests in total.  All products are lyophilized.

Histosonda Thyroglobulin consists of a segment of single-stranded DNA complementary to expressed RNA with a length of 552 nucleotides. This probe has been labeled with Digoxigenin.

STORAGE CONDITIONS

Supplied reagents are stored at room temperature until their expiration date. After being reconstituted the probes will remain stable for two weeks at 4ºC in a DNAase-free environment.  The Anti-Digoxin can be stored at 4ºC for 1 month and the Proteinase K must be used immediately and cannot be stored.  Do not use these products after their expiration dates.

SAMPLES

Any paraffin block section in which Thyroglobulin RNA presence is to be studied. Sections of 4-6 micrometers in width are sufficient to conduct the study. Preferably, the cut should be recent (no more than thirty days old). Assay results are not affected by block age. Studies have been carried out in the manufacturer's laboratories using 20 year old

paraffin blocks with optimal results.

INTERPRETATION OF RESULTS

Samples in which Thyroglobulin expression is observed will show a brownish color in the cell cytoplasm, which will contrast over the blue-violet background given by hematoxylin staining. The pathologist will evaluate the results according to their experience, drawing conclusions from the staining of the sample in parallel with the staining observed in positive and negative controls.

ASSAY LIMITATIONS

The Kit Histosonda Thyroglobulin has been optimized to detect RNA expression in formalin-fixed, paraffin-embedded tissues. Its use is not recommended for other types of samples or preparation techniques.

The correct operation of this kit has been validated using the protocols indicated in the instructions manual. The use of other procedures or the modification of the recommended protocols may lead to erroneous results.

The results from this assay must be evaluated by the pathologist in combination with the rest of available patient clinical data.

In order to obtain optimal and reproducible results it is important to rigorously maintain the time and temperature conditions indicated in the procedure.