U.S. flag

An official website of the United States government, Department of Justice.

DNA Extraction and Quantitation for Forensic Analysts

Yield Gels

Home  |  Glossary  |  Resources  |  Help  |  Contact Us  |  Course Map

Image of yield gel technique
National Institute of Justice (NIJ) (see reuse policy).

The yield gel technique is a semi-quantitative/qualitative assay that allows for the estimation of the concentration and quality of DNA in a specimen. The method consists of the electrophoresis of DNA in an agarose gel matrix incorporating a fluorescent intercalating dye such as ethidium bromide (EtBr). The concentration of a sample can be determined by comparing the intensity of the fluorescence of the sample to that of the calibration standards.

One of the benefits of yield gels is the ability to assess the quality of the DNA sample. Larger (undegraded) DNA fragments migrate at a slower rate than those of lower molecular weight. Degraded DNA will consist of lower molecular weight fragments.

Safety Note:

Ethidium bromide (EtBr) is a known carcinogen.

Read more about capillary electrophoresis in course: Amplified DNA Product Separation.

(You may have to enter your Userid and password.)

Back Forward