DNA Marker Selection Guide

----Clean Background, Stable Band Patterns, Precise Sizes

 

DNA Markers are a combination of DNA fragments with different molecular weights. Their primary use is to co-migrate with sample DNA in agarose gel electrophoresis to separate the DNA molecules. By comparing the size and brightness of the sample bands with those of the DNA Marker, one can roughly estimate the molecular weight and concentration of the sample DNA in solution. YEASEN DNA Markers cover a molecular weight range from 100 bp to 15 kb, meeting the needs of most experiments.

Product Features

  1. Strong stability, can be stored at room temperature for 3-6 months;
  2. Clean background, stable band patterns, and precise sizes;
  3. Contains reference bands with known concentrations for easy positioning and semi-quantitative analysis;
  4. Includes loading buffer for direct electrophoresis, convenient and quick;
  5. Comes with a 5× loading buffer for sample loading.

Electrophoresis Diagram

Attention Points 

  1. Storage Method: Stable storage at room temperature for 3 to 6 months; for longer periods, store at 4°C or -20°C.
  2. DNA Marker is suitable for analyzing DNA bands in agarose gel electrophoresis and is not recommended for use in polyacrylamide gel electrophoresis.
  3. Selection of gel concentration and buffer solution:

Agarose Concentration

Effective Separation Range (bp)

Recommended Buffer

0.5%

2,000-50,000

1×TAE

0.8%

800-10,000

1×TAE

1.0%

400-8,000

1×TAE

1.2%

300-7,000

1×TAE

1.5%

200-3,000

1×TAE/0.5×TBE

2.0%

100-2,000

1×TAE/0.5×TBE

3.0%

25-1,000

0.5×TBE

【Note】: For large fragments, choose a low-concentration gel and use a TAE buffer system for electrophoresis; for small fragments, choose a high-concentration gel and use a TBE buffer system for electrophoresis.

  1. Selection of Nucleic Acid Stains:

EB (Ethidium Bromide) is a highly sensitive fluorescent dye with a maximum excitation wavelength of 302 nm, which can be used to observe nucleic acids in agarose and polyacrylamide gels. EB intercalates with the bases in nucleic acids and is known to be toxic.

YeaRed (Cat#10202ES76) and YeaGreen (Cat#10204ES76) are new non-toxic nucleic acid dyes with a unique oily molecular structure that cannot penetrate cell membranes to enter cells, are not easily volatile or sublimable, and thus are not inhaled by humans, ensuring the safety of the experimenter. Ames test results also show that YeaRed and YeaGreen have no mutagenicity at gel staining concentrations, making them a safe and non-toxic alternative to the highly carcinogenic EB. Additionally, YeaRed has the same spectral characteristics as EB, so it can perfectly replace EB without changing the existing imaging system.

Q&A

Q1: Why do the high molecular weight bands of the DNA Marker drag and not separate well?

A1: The nucleic acid dye does not bind sufficiently with the DNA Marker. Since high molecular weight bands require more nucleic acid dye, if the dye is not saturated, the high molecular weight bands are more susceptible to migration effects, leading to dragging and poor separation. It is recommended to reduce the amount of DNA Marker used (it can be diluted with water by 5 times and then 8-10 μL can be loaded) or to increase the concentration of the nucleic acid dye. 

Q2: Why are there no bands or weak bands for DNA?

A2:

  1. Insufficient DNA loading, increase the amount loaded;
  2. The DNA band has run out of the gel;
  3. The DNA band is obscured by the tracking dye;
  4. Nucleic acid dye was not added to the gel;
  5. The agarose gel has been left for too long, it is recommended to prepare and use it immediately.

Q3: Why are the DNA Marker bands diffuse?

A3:

  1. Partial degradation of DNA, check if the storage conditions are too warm;
  2. The voltage during electrophoresis is too low, causing the DNA bands to diffuse. It is recommended to run the gel at 110V-130 V for more than 45 min;
  3. The concentration of the agarose gel is not appropriate, prepare according to the recommended gel concentration in the manual;
  4. The quality of the agarose gel is poor, it is recommended to prepare a new one.

Q4: Why do sample bands appear to be of different sizes compared to DNA Marker bands?

A4:

  1. DNA migration is not only related to the actual size but also to whether it is combined with proteins, ion state, DNA structure, gel, and other factors. The electrophoretic migration rate of nucleic acids is related to the ratio of DNA/dye, and when the amount of nucleic acid dye is insufficient, it can lead to larger migration rate errors;
  2. If the sample contains a high concentration of salt ions, it can also cause significant migration errors;
  3. If the amount of sample loaded significantly differs from the amount of DNA Marker bands or if the volumes differ significantly, it can also cause larger migration errors.

Ordering Information

Product Orientation

Product Name

Product Number

Specifications

DNA Marker

GoldBand DL2000 DNA Marker

10501ES60/80

100 T/10×100 T

GoldBand DL5000 DNA Marker

10504ES60/80

100 T/10×100 T

GoldBand 100bp DNA Ladder

10507ES60/80

100 T/10×100 T

GoldBand 1 kb DNA Ladder

10510ES60/80

100 T/10×100 T