Histosonda®

Serum albumin is produced by the liver in humans.

Human serum albumin has a molecular weight of 69 Kd and is the most abundant protein in the serum. Its main purpose is substance transport, as well as contributing to the osmotic pressure of blood.

Until now, antibodies against serum albumin have been developed in order to identify hepatocarcinomas but the results have been poor due to the heavy tissue background they produce when used in immunohistochemistry.

CENBIMO has produced a single-stranded DNA probe that consists of three segments of single-stranded DNA complementary to expressed RNA, with lengths of 305, 370 and 377 nucleotides.

This probe is useful when diagnosing hepatocarcinomas in difficult situations (fine needle hepatic biopsies), and to distinguish them from metastatic tumors from other origins, as well as for diagnosing Combined hepatocellularchollangicarcinoma (CHC).

INTENDED USE

For use in In Vitro Diagnosis.

The Kit Histosonda Serum Albumin is useful for detecting hepatic cells, both tumoral and not.

WARNINGS AND PRECAUTIONS

The Kit Histosonda Serum Albumin 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 Serum Albumin; 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 Serum Albumin consists of three segments of single-stranded DNA complementary to expressed RNA, with lengths of 305, 370 and 377 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 human serum albumin 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 serum albumin 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 Serum Albumin 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.

BIBLIOGRAPHY

Ohguchi S, Nakatsukasa H, Higashi T, Ashida K, Nouso K, Ishizaki M, Hino N, Kobayashi Y, Uematsu S, Tsuji T.:

Expression of alpha-fetoprotein and albumin genes in human hepatocellular carcinomas: limitations in the application of the genes for targeting human hepatocellular carcinoma in gene therapy. Hepatology. 1998 Feb;27(2):599-607.

D'Errico A, Baccarini P, Fiorentino M, Ceccarelli C, Bonazzi C, Ponzetto A, Scoazec JY, Mancini AM, Grigioni WF. Histogenesis of primary liver carcinomas: strengths and weaknesses of cytokeratin profile and albumin mRNA detection. Hum Pathol. 1996 Jun;27(6):599-604.

Tickoo SK, Zee SY, Obiekwe S, Xiao H, Koea J, Robiou C, Blumgart LH, Jarnagin W, Ladanyi M, Klimstra DS.

Combined hepatocellular-cholangiocarcinoma: a histopathologic, immunohistochemical, and in situ hybridization study. Am J Surg Pathol. 2002 Aug;26(8):989-97.

Oliveira AM, Erickson LA, Burgart LJ, Lloyd RV.:

Differentiation of primary and metastatic clear cell tumors in the liver by in situ hybridization for albumin messenger RNA. Am J Surg Pathol. 2000 Feb;24(2):177-82.