Genomic DNA Spooling (Lab 4B)
Our Genomic DNA Spooling kit allows for 8 groups of 2-4 students to spool salmon testes DNA onto a spooling rod. This lab module allows students to precipitate the DNA from solution before spooling (winding) onto a rod. The recovered DNA is returned to solution and the students then use G-Biosciences’ NUCLEIC dotMETRIC kit to estimate the amount of DNA recovered.
A known amount of salmon testes DNA solution is dissolved in TE buffer, mixed with NaCl, and placed in a vessel (beaker or tube). A layer of 95% ethanol is added to the DNA mixture. Using a glass rod or wooden spooling stick, the ethanol can be gently pushed down into the DNA solution. The charged DNA molecules move away from the ethanol and can be scooped up and swirled around a glass rod or wooden spooling stick. This is called DNA spooling. DNA spooling can isolate long strands of DNA from a solution. The tighter the strands are spooled, the more water is pushed out and, the DNA goes from looking like goopy mucous to white strands. Pure, dry crystalline DNA is white. Spooled DNA is scraped off the rod and mixed into a small amount of TE buffer for storage. After a day or two in the TE buffer, the DNA strands unwind and dissolve back into solution. Samples of the salmon DNA may be studied using indicators or gel electrophoresis.
This laboratory activity is adapted from “Laboratory 4b: Precipitating DNA out of Solution: DNA Spooling” from Biotechnology: Laboratory Manual by Ellyn Daugherty. For more information about the program, please visit www.emcp.com/biotechnology. This kit is produced under license from Paradigm Publishing, Inc., a division of New Mountain Learning.