The 12-Gel Comet Assay Unit

Description:

The 12-Gel Comet Assay Unit^TM   (Part number CA110-01)
(Patent Pending.  Design Copyright 2010)

The 12 Gel Comet Assay unit ^TM is designed to increase the throughput of the comet assay, and to facilitate incubation of cells/nucleoids with reagents, enzymes etc. It allows the preparation and processing of 12 comet assay gels on one microscope slide. The apparatus forms isolated incubation wells where cells can be immobilised, treated with geno-toxic compounds before lysis, and/or incubated with lesion-specific enzymes, cell extracts, etc. after lysis.  

The 12 Gel Comet Assay unit^TM is supplied ready assembled. The unit is easily disassembled for use in the comet assay.

Assembly and Use

( Note.  Please note: DO NOT remove the locating screws, when disassembling the unit.) The locating screws remain in place so that when the clamps are removed the top plate is simply lifted off the metal base plate. The screws will then hold the clear plate off the bench. The gasket seal is easily removed from the microscope slide, which has been placed in position to demonstrate how the unit is assembled)
Simply place the agarose (or Pagarose^TM (an experimental coating not yet commercially available)) coated microscope slide into the metal base plate holder, position the gasket seal, then attach the top plate pushing the screw corners into the drilled holes to position the clear top plate. Tighten the unit with the gate clip clamps to form a good seal using the thumb wheel on the clamp. (They only need lightly tightening.) Incubation wells are thus formed between the microscope slide, gasket seal, and top plate.

Aliquots of 5 µl of cell suspension in low melting point agarose are then pipetted into the wells and onto the slide of the 12 Gel apparatus, taking care to avoid the gel touching the sides of the well. Incubation before and/or after lysis takes place in situ. The slide is then removed from the apparatus for electrophoresis and scoring.

Some applications

•  Genotoxicity testing: different concentrations of a chemical under test can be administered to individual gels on the same slide.
• Analysis of DNA damage using lesion-specific enzymes: different enzymes can be applied, after lysis, to identical cell samples on one slide.
• In vitro DNA repair: incubating specifically damaged DNA substrate with cell extracts to measure incision capacity.
• Bio-monitoring: several samples of lymphocytes (for example) can be analysed in parallel on a single slide.
• Fluorescent in situ hybridisation: the isolated, sealed wells provide ideal conditions for incubation of nucleoid DNA with probes for individual genes, chromosomes, centromeres, etc.

General Information to use Apparatus.

The 12 Gel Apparatus can be used in different ways, according to experimental requirements.

•  The gels can be set on the slide before assembling the complete unit. Simply place the slide on the base plate and centre the gels over the marked positions; allow to set and then assemble the unit. Place the gasket on the slide avoiding contact with the gels.
• The metal baseplate can be pre-chilled to ensure that the gels set quickly, without spreading out on the slide.
• After treating cells with (different concentrations of) genotoxins, it may be convenient to remove the slide and carry out lysis in a staining jar.
• Conversely, if the experiment involves enzyme incubations, it may be convenient to carry out lysis and washing steps in a staining jar before placing the slide in the 12 Gel Apparatus.

Useful reference
Collins AR (2004) The comet assay for DNA damage and repair. Molecular Biotechnology 26, 249-261
www.newgeneris.org for download of comet assay training DVD and CD.

Ordering
The unit is sold as a complete 12 Gel Apparatus or its component parts which make up the product:
 The 12-Gel Comet Assay Unit^TM Part number CA110-01

Component Parts.

The 12 Gel Apparatus consists of:
(i)    Part number:CA100-1 Metal Base Plate
Metal base plate on to which the pre-coated microscope slides fit

(ii)    Part number:CA101:1 Clear Top Plate
A clear top plate, to be placed on top of the gasket seal.

(iii)    Part number:CA102-1 Moulded twelve well Rubber Gasket
A moulded gasket with twelve wells , which fits on top of the microscope slide

(iv)    Part number: CA103-2  Tension Clamps
Two  tension clamps to hold the top and bottom plate in place and apply pressure to it,
ensuring the gasket forms a good seal between the wells, microscope slide and plates.

(v)    Part Number. CA:104 Well Cover
Incubation well cover designed to line up and fitted by simply pushing onto wells.

Re-Ordering:   The above parts may be purchased individually as spares for the 12 Gel Comet Assay Unit^TM