Madge Gel


Microplate Array Diagonal Gel Electrophoresis (MADGE) was invented at the Division of Cardiovascular Genetics, Department of Medicine, University College London Medical School.  It has been demonstrated that the MADGE system works with both Agarose and Polyacrylamide gels and provides a simple and effective high throughput method of analyzing PCR products and PCR digests used in the typing of genetic variation (genotyping).

Most PCR reactions are preformed in the standard 96 well format with a 9 mm pitch between the wells. The MADGE system uses the same 96 well format to form the wells in the gel thus avoiding recoding of samples and enabling 8, 12 and 96 well pipetting of PCR products directly to the gel. The well pattern in the gel is placed askew so the electrophoretic pathway runs diagonally through the gel giving a run path of 26.5 to 50 mm long.  For many applications this is long enough to provide good resolution between small molecules.

MADGE Gels have application in several areas: detecting single nucleotide polymorphism (SNP) in genotyping studies, sizing or conformational analysis of insertion/deletion variants, size checking in expressed sequence tag (EST) analysis or heteroduplex analysis.  An article was recently published in the Journal of Physiological Genomics that illustrates the advantages of the MADGE technique with some high resolution photographs of developed MADGE gels.

The MADGE Gel formers are sold by MadgeBio in the UK.  More information on the MADGE Gel system and applications can be found on their web site  

V&P Scientific, Inc. has developed 96 MULTI-BLOT ™ Slot Pin Replicators to load the wells in the MADGE gel. This greatly simplifies applying PCR product the MADGE gel wells.

To load a  MADGE gel, electrophoresis buffer is flooded over the gel plate and a Slot Pin MULTI-BLOT™ Replicator carrying specimens in gel loading buffer (Ficoll or sucrose) is carefully lowered by hand until the pins touch the buffer.  The gel loading buffer carrying the PCR product is denser than the electrophoresis buffer so when the slot pins touch the electrophoresis buffer the PCR product "falls" out of the slot pin and into the gel well. 

MADGE Gels come in two styles: Standard and Stretch.  The Standard MADGE Gel  has a track length of 26.5 mm and the Stretch MADGE Gel  has a track length of 50 mm. 

Click here for a list of published articles that cite the products on this page.

We make many different slot pin MULTI-BLOT™ Replicators so any volume from 0.1 to 10 ul could be delivered to the wells. However most investigators use either the 2 or 5 ul slot pin MULTI-BLOT™ Replicators.

If you are transferring DNA, cDNA or other materials in hydrophobic solutions you will find that using our new V&P Pin Cleaning Solution will greatly increase the precision of delivery.  For an explanation see the FAQ page and the V&P Pin Cleaning Solution page.

2 ul slot pin MULTI-BLOT™ Replicator.....VP 408S2

5 ul slot pin MULTI-BLOT™ Replicator.....VP 408S5 

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Lint Free Blotting Paper


Integral to the cleaning process is the blotting step between baths.  We have found an inexpensive lint free blotting paper (VP 522) to use that doesn't transfer lint particles to the slot pins as many blotting papers or paper towels can do. Lint in the slots can interfere with the quantitative transfer of liquid.  We strongly recommend that you use these blotting pads over several layers of paper towels.




We suggest that you buy 4 other inexpensive items when you purchase a Replicator that will make using the Replicators easier, safer and more reproducible. The VP 381 is a registration device that aligns the Replicator pins to the center of the wells. This is very important as you do not want the pins to touch the side of wells as you remove the pins because that will knock off the hanging drop at the pin tip.  The VP 420 is a glass alcohol reservoir that is used in the sterilization of the Replicators by flaming. Some labs use plastic reservoirs but if flaming alcohol drops into them the plastic burns too dumping flaming alcohol all over the counter.  The VP 425 is pin cleaning brush that is used to kept the Replicator pins clean so they will carry the same amount of liquid each time. VP 110 is a Pin Cleaning Solution that is used to clean and treat the pin tips when they can't be flamed.

Click here for a list of published articles that cite using the products on this page.

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