A Western Blot is a molecular biology tool that scientists use to separate and detect specific proteins. In this video, Jayme Dyer describes how a Western Blot was used in a novel approach to determining the sex of baby turtles. This video introduces the core conceptual understanding of how a Western Blot works without getting bogged down in details required to actually run a Western Blot. Be sure to check out the Tortoise Bloopers from this video:    • Tortoise Bloopers  

0:00 Introduction
0:24 How do you determine the sex of a baby turtle?
1:30 What is a Western Blot?
2:43 How to interpret a Western Blot
3:10 How does a Western Blot work?
3:22 Electrophoresis (& What is a Coomassie Stain?)
4:57 Transfer
6:09 Blotting
7:19 Why is it called a "Western Blot?"
7:50 Western Blot = Immunoblot & Immunoassay
8:02 Results from research study using a Western Blot to determine the sex of baby turtles

The paper about determining the sex of baby turtles is:
B. Tezak, I. Sifuentes-Romero, S. Milton, J. Wyneken, Identifying Sex of Neonate Turtles with Temperature-dependent Sex Determination via Small Blood Samples. Sci Rep 10, 5012 (2020). https://doi.org/10.1038/s41598-020-61...

Photo, Video and Music Credits:

Video of baby leatherback turtles leaving nest by Tyler Karaszewski CC-BY 2.0
Video of climate change visualization by Antti Lipponen (  / anttilip  ) CC-BY 4.0
Photo of snorkeling scientist with turtle by NOAA – Public Domain
Photo of scientist preparing mounting on turtle by Adam Li, NOAA/NMFS/SWFSC CC-BY 2.0
Example Western Blot CC-BY 4.0 from "Angiostrongylus cantonensis cathepsin B-like protease (Ac-cathB-1) is involved in host gut penetration". Parasite 22: 37. DOI:10.1051/parasite/2015037
Image of gel electrophoresis of DNA gel on UV box by TransControl CC-BY SA 3.0
Image of DNA gel adapted from R. Patra, et al., Multiple Infection and Microdiversity among Helicobacter pylori Isolates in a Single Host in India. PLOS ONE 7, e43370 (2012).
Mouse, Rabbit, and Goat cartoons by DataBase Center for Life Science (DBCLS) CC-BY 4.0
Photo of Gel Doc by Wiki210397 CC-BY SA 4.0
Photo of Edwin Southern by Gitschier J (2013) Problem Solved: An Interview with Sir Edwin Southern. PLoS Genet 9(3): e1003344. CC-BY 4.0

Hammock Fight music by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license.

Photos and video of SDS-PAGE and Western Blot steps by Allie McClure and Berta Canal, used with permission.

Many thanks to Shannon Michele for letting me borrow her tortoise.


Image of Western Blot in the video thumbnail is from Copy-number and gene dependency analysis reveals partial copy loss of wild-type SF3B1 as a novel cancer vulnerability, CC-BY https://doi.org/10.7554/eLife.23268

This video is copyright Jayme Dyer 2021, published under the Creative Commons CC-BY SA 4.0 license.

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