Website Search
ID 16961

DNA Isolation Step 1: Preparing the Sample

Description:
Jason Williams, DNA Learning Center, shows how to prepare an animal or plant sample for DNA isolation.
Transcript:
To begin the protocol, first you need to get a sample of the individual things that you’ve collected. In this case, I have a broad leaf from a maple tree, I have some salmon that’s here, and I have some insects, which are probably crickets. So, what I’ll need is one tube that I’ve labeled for each one of my samples. When you label your samples, and I’m just going to use a Sharpie, give them the designation – I’m calling this one Sample 1 – I’m giving it a date that I’ve actually collected it on or processing it on, and I want to label it on the side as well as the top of the tube just so I can always be sure. Now when you collect your sample for DNA extraction or when you actually take a small piece of it, less is actually more. It’s actually very important to get a small amount of the sample. For a leaf what we can use is actually a blue pipette tip; this is a P1000 tip, and we can actually use it to make a cutout of the leaf, and really what you’re going for is a very, very small section, so I’m just going to take that. And when you use the tip you actually get a nice round cutout, and I’ll use the forceps to grab this out of the pipette tip. Now working with fish or other things, such as insects, you’re looking for about 10 to 20 mg, which is a very, very small amount of sample. To illustrate with this piece of salmon, I’m just going to take the scissors, take my forceps and actually cut off a very, very small amount. It’s a little bit less than the size, perhaps, of a pencil eraser, and it’s just that amount that you need in order to get quite a bit of DNA from. I’ll take this, put it into my tube, and of course I want to make sure that I label my tube so that I don’t forget what sample this is. In some cases, when doing DNA barcoding, you’re actually going to be the author of the barcode. What that means is that not only did you collect DNA and sequence it in order to obtain the DNA barcode sequence, but that you preserved the specimen so that other scientists could study it. What that means is that when you’re collecting a specimen like this cricket, you’re not going to damage the whole insect; you actually want to take just a small amount so that it’s actually identifiable by traditional taxonomy methods. So in this case, we’re just going to take a leg from this cricket, and the rest we can pin and label and store so that we can be the author of the barcode. Here I have a small amount, and that’s really just enough for us to do the DNA barcoding with.
Keywords:
DNA, barcoding, lab, protocol, isolate, isolation, specimen, sample, pipette, extract, extraction, precipitate, precipitation, centrifuge, identification, DNALC, CSHL, DNA Learning Center, Cold Spring Harbor Laboratory, high school, middle school, Urban Barcode Project, gene, genetic
Downloads:
Creative Commons License This work by Cold Spring Harbor Laboratory is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.

Related content:

17003. DNA Barcoding Protocol: Isolating DNA
A DNALC instructional video showing the steps involved in isolating DNA
16959. DNA Barcoding Protocol: Isolating DNA
A DNALC instructional video showing the steps involved in isolating DNA
16962. DNA Isolation Step 2: Extracting the DNA
DNA Isolation - Step 2 of 4: Extracting DNA
16963. DNA Isolation Step 3: Precipitating the DNA
DNA Isolation - Step 3 of 4: Precipitating DNA
17005. Urban Barcode Project: 2014 Participant Reflections
Students participants in the 2014 Urban Barcode Project describe their projects and reflect on the experience, including the challenges and rewards of doing independent student research.
17002. Urban Barcode Project: 2013 Participant Reflections
Students and teachers who participated in the 2012 Urban Barcode Project reflect on the experience, including the challenges and rewards of doing independent student research.
16979. DNA Barcoding
An animation introducing the concept of a DNA barcode, how it works, and what type of research questions DNA barcoding can answer.
16974. Urban Barcode Project: 2012 Participant Reflections
Students and teachers who participated in the 2012 Urban Barcode Project reflect on the experience, including the challenges and rewards of doing independent student research.
16969. Urban Barcode Project 2012: 3rd Prize Presentation: Killifish
UBP 2012 Finalist presentation: Assessing the Identification, Distribution, and Diversity of Killifish in New York City Coastal Waters
16975. Urban Barcode Project 2012: Honorable Mention Presentation: U.S. Customs
UBP 2012 Finalist presentation: DNA Barcoding Exotic Agricultural Pests Seized by the U.S. Customs and Border Protection
Cold Spring Harbor Laboratory
CSHL HomeAbout CSHLResearchEducationNews & FeaturesCampus & Public EventsCareersGiving