Tissue Microarray

Multi-tissue blocks were first introduced by H. Battifora in 1986 with his so-called "multitumor (sausage) tissue block" and modified in 1990 with its improvement, "the checkerboard tissue block". In 1998, J. Kononen and collaborators developed the current technique, which uses a novel sampling approach to produce tissues of regular size and shape that can be more densely and precisely arrayed.

The TMA technology is a technical procedure that combines tens to hundreds of paraffin-embedded tissue specimens into a single paraffin block.
Cylindrical tissue cores (typically 0.6-2.0 mm in diameter) are acquired from one or more representative region(s) of a paraffin embedded
tissue block (donor block) and then precisely arrayed into a new "recipient" paraffin block, using a custom-built instrument.

Up to 200 consecutive sections of 4-5µm thickness can be sliced from each TMA block, mounted on a microscope slide and processed like ordinary tissue sections with a wide range of techniques (histochemical staining, immunohistochemical and immunofluorescent staining, FISH).

TMA advantages

TMAs have a number of advantages compared with conventional techniques.

• The speed of molecular analyses is increased by more than 100-fold
• Precious tissues are not destroyed
• Large number of molecular targets can be analyzed from consecutive TMA sections

Additional TMA Applicatons:

CELL MICROARRAY (CMA)

CMA evolved from TMA with the exception that fixed cells are used instead of tissues. Cells are grown in culture, suspended in agarose and embedded in paraffin.

• Immunocytochemistry analysis (IC) of any type of cells
• High-throughput screening of hundreds of cell samples on a single slide
• Several slides can be generated from a paraffin recipient block ready to be assayed with different markers

TISSUE CORE PICKING & DISPENSING

• Galileo 4500 can be used for TMA, CMA and as sample picker for nucleic acids (DNA and RNA) extraction and for protein isolation using appropriate fixative
• The tissue cores extracted from precise regions may be dispensed into dedicated vessels for further processing such as DNA, RNA, miRNA and protein extraction. Microfuge vials, strips or microtiter plates may be used,depending on the downstream applications. Parallel analyses on the same specimen can be performed simultaneously

NUCLEIC ACIDS EXTRACTION

• DNA extracted from tissue cores (1mm and 3.5mm) from human prostate, uterus and colon using silica based matrix (Malferrari et al., 2002)
• The agarose gel (0.8%) shows the quality of DNA extracted and the PCR amplification of the BRCA1 gene with specific primers

Additional TMA Applicatons:

CELL MICROARRAY (CMA)

CMA evolved from TMA with the exception that fixed cells are used instead of tissues. Cells are grown in culture, suspended in agarose and embedded in paraffin.

• Immunocytochemistry analysis (IC) of any type of cells
• High-throughput screening of hundreds of cell samples on a single slide
• Several slides can be generated from a paraffin recipient block ready to be assayed with different markers

TISSUE CORE PICKING & DISPENSING

• Galileo 4500 can be used for TMA, CMA and as sample picker for nucleic acids (DNA and RNA) extraction and for protein isolation using appropriate fixative
• The tissue cores extracted from precise regions may be dispensed into dedicated vessels for further processing such as DNA, RNA, miRNA and protein extraction. Microfuge vials, strips or microtiter plates may be used,depending on the downstream applications. Parallel analyses on the same specimen can be performed simultaneously

NUCLEIC ACIDS EXTRACTION

• DNA extracted from tissue cores (1mm and 3.5mm) from human prostate, uterus and colon using silica based matrix (Malferrari et al., 2002)
• The agarose gel (0.8%) shows the quality of DNA extracted and the PCR amplification of the BRCA1 gene with specific primers