Collection: Electrophoresis, Gels & Ladders

Lower percentages resolve larger fragments: roughly 0.7% for 5–10 kb, 1–1.5% for everyday PCR products, and 2% for fragments between 0.2 and 1 kb. Most labs never leave the 0.7–2% range. Below 0.7% the gel becomes awkward to handle, which is where high-strength or specialty agaroses earn their place.

EEO is electroendosmosis — a flow of water toward the cathode driven by sulfate and carboxyl groups fixed in the agarose matrix. That counterflow works against the DNA and produces smeared, blurred zones. Low-EEO agarose has been purified to a lower sulfate content, so nucleic acids migrate faster and bands stay sharp; Condalab Agarose D1 Low EEO and Benchmark Agarose LE (EEO ≤0.13-mr) both belong to this class.

Whenever the DNA has to come back out of the gel intact. LM agaroses melt and gel well below nucleic acid denaturation temperatures, so an excised band can be remelted, digested with agarase, or carried straight into ligation, restriction digestion or PCR. Condalab Agarose LM covers fragments from about 1000 bp upward and LM Sieve resolves below that, while Benchmark Agarose LM spans 200 bp to 25 kb.

Bracket the band you expect rather than merely covering it — a 100 bp ladder for products under about 1 kb, a 1 kb ladder across roughly 250 bp to 10 kb for restriction digests, and a high-range or lambda/HindIII marker above 10 kb. Loading the ladder in a lane next to your samples, not at the far edge of the gel, makes the size call considerably more reliable.

The Condalab agarose range and Benchmark Scientific agaroses are supplied here by Danyel Biotech, with local stock and advice on which grade fits the application. Send your catalog list and we will come back with a quote.