High Resolution
Spreadex® for sensational resolution:
Spreadex® gels provide highest resolution power in the size range of 50 bp to 1000 bp. The resolving power is three times higher than the resolving power of any other synthetic gel matrix.
The synthetic polymers used for Spreadex® form an unique three-dimensional structure in which the polymers meet the migrating DNA fragments with increasing resistance. Selective retardation of long DNA molecules results in larger spacing between fragments. The bands become more spread out along the gel length, but remain sharp, even at high running temperatures.
Spreadex® gels do not melt at high temperatures (95°C) and do not inhibit DNA polymerases and ligases.
Consequently, bands identified by a conventional dye can be excised with BandPick™ and used directly for reamplification, sequencing or cloning.
Each Spreadex® gel is characterized by an exclusion limit (EL). DNA molecules longer than the indicated EL do not migrate in the gel even after prolonged electrophoresis. The gels are available in six different exclusion limits (EL 300, 400, 500, 600, 800, 1200).
Spreadex® EL 300 and EL 400 gels resolve fragments of only 1 bp difference for a total fragment length of up to about 150 bp. DNA fragments differing by 4 bp are easily resolved on all Spreadex® gels.
Special Features of Spreadex®
- Sensational resolution: down to1 bp on 8 cm running distance, 4 bp on 4 cm running distance
- High throughput: analysing up to 2500 samples per day
- Direct recovery: identified bands can be excised and directly used for PCR, sequencing and cloning
- Accurate sizing: DNA runs fragment size-dependent only. Sequence-dependent mobilities are largely eliminated during high temperature electrophoresis (55°C)
- Zooming: zoom in on your fragment size of interest by choosing the desired exclusion limit
- High sensitivity: since bands are sharp and highly focused, very little DNA is required per band for detection
Spreadex® General Notes
- Spreadex® exists in six different exclusion limits (EL): EL 300, 400, 500, 600, 800, 1200. All molecules longer than the indicated EL mentioned above do not enter the gel.
- Always use 30 mM TAE buffer. Borate is not compatible with Spreadex®.
- Stain after electrophoresis
- Storage: horizontally at 4°C (40°F), do not freeze!
- Shelf life: at least 3 months (max. 6 months)
Precast Gels Overview: Size Range & Resolution:
Type of Gel | Optimal Size Range bp | Resolution | Special Features | |
---|---|---|---|---|
Spreadex® |
50-1000 | 1 - 4 bp |
highest |
|
EL 1200 | 250-800 | 4 bp | ||
EL 800 | 200-500 | 4 bp | ||
EL 600 | 150-350 | 4 bp | ||
EL 400 | 65-250 | 1 bp* |
Different Formats:
AL's ready-to-use gels are available in 8 different formats. They allow the analysis of up to 400 samples per gel. AL-Diagnostic provides two main formats of gels:
1) Mini Gels
2) Wide Mini Gels - 2 or 4 gels per presentation.
Mini 8/12 wells

Running distance:
87 mm for 8 samples
57 mm for 12 samples
Wide Mini 2x13 and 4x13
Running distance:
87 mm for 2x13
40 mm for 4x13
Wide Mini 2x25 and 4x25
Running distance:
87 mm for 2x25
40 mm for 4x25