25/100 bp Mixed DNA Ladder is designed for estimating sizes of double-stranded DNAranging from 25 to 2,000 bp. It consists of total 17 DNA fragment markers: 8 markers from 25 to 200 bp in 25 bp increments, 8 markers from 200 to 1,000 bp in 100 bp increments, and an additional marker of 2,000 bp.
If the DNA size and concentration of the agarose gel do not match, DNA separation may not be sufficiently performed.
Please refer to the table below and use the appropriate concentration of agarose gel.
Also, DNA may not be separated correctly due to insufficient electrophoresis time, please conduct electrophoresis for a sufficient amount of time, as long as the sample does not pass through the agarose gel.
Concetration of agarose(%)
DNA size range (bp)
Fig 1. Agarose gel concentration for resolving linear DNA molecules.
* Introduction to Agarose and Polyacrylamide Gel Electrophoresis Matrices with Respect to Their Detection Sensitivities
The recommended usage is based on the use of EtBr, a different usage is required depending on the detection dye or transilluminator that is recently used.
Also, please check the composition and pH of the TAE and TBE buffers.
This problem can occur if the gel was manufactured or stored incorrectly. Since fluorescent dyes are produced as substitutes for EtBr, it has a nature that fluorescent substances decompose by light.
Therefore, while adding a dye while producing a gel, it can decrease clarity over time.
If the size of the nucleic acid is small, we recommend to use TBE buffer rather than TAE buffer.
The ladder consists of linear DNA, so accurate size comparison is possible in the linear form.
Also, Plasmid DNA is extracted by Open Circular/Linear/Supercoiled, in order to check the exact size, we recommend enzyme cutting.
Two buffers have differences depending on the purpose and characteristics of use.
Contains Tris, Acetic acid, EDTA
Contains Tris, Boric acid, EDTA
When the DNA molecular weight is large (size of 12 kb or more)
When the DNA molecular weight is small (size of 1 kb or less)
low ionic strength
high ionic strength
Buffering capacity is low, and cannot be used multiple times
※ When the voltage used for electrophoresis is 5 V/cm (5 V per 1 cm distance between both electrodes) or less, a clear DNA band can be obtained.
* There is a slight difference in the voltage used for each device.
High buffering capacity, can be used multiple times
Buffer replacement required for long-term electrophoresis
Relatively less heat is generated, so it can be used for a long time compared to TAE Buffer
※ DNA Elution Method: TAE Buffer is recommended as borate plays a role in interfering
※ DNA Sequencing: TBE Buffer is recommended due to its high buffering capacity and low conductivity
※ Role of EDTA: Preventing DNA degradation by DNase inhibition, maintaining (-) charge of DNA required for electrophoresis
TBE Buffer contains boric acid (borate), and if it is manufactured at 5X or more, crystallization occurs when the temperature is below room temperature.
For this reason, TBE Buffer is recommended to use as soon as possible upon arrival.
As single-stranded RNA and DNA have different electric charges, the running time is different even with the same length.
DNA markers can be used to determine the approximate size, but to determine the exact size, RNA-exclusive markers should be used.