DNA is Everywhere!

DNA is Everywhere!

In this lesson students learned all about deoxyribonucleic acid, more commonly known as DNA. After getting a brief overview of DNA’s role in the storage of genetic information, students followed a DNA extraction protocol experiment and successfully extracted DNA from strawberries/bananas by breaking down the cell membranes with detergent, then freeing the DNA from its protective proteins (histones) by using a protease (an enzyme that breaks down protein – actually Accent Meat Tenderizer!). By breaking down the cell wall, membrane, and nuclear membrane, students were able to isolate the nucleic acids.

They then added some very cold isopropyl alcohol to the resulting lysate (the fluid and cell remnants left over when the cells were broken up), which caused the DNA to become visible at the border between the aqueous solution and the alcohol. The addition of alcohol to the cell lysate allows the nucleic acids become visible without a microscope! The activity involved a number of different steps and helped emphasize the importance of following directions carefully. The young scientists were rewarded for their diligence by seeing DNA in their test cups at the end of the lab!

 

¡El ADN está en todos lados!

En esta clase los estudiantes aprendieron sobre el ácido desoxirribonucleico, más conocido como ADN. Después de hacer una pequeña revisión sobre el rol de ADN como almacén de información genética, los estudiantes siguieron un protocolo de extracción de ADN. Los estudiantes extrajeron exitosamente el ADN de germen de trigo. Para esto, primero tuvieron que romper las membranas de las células con detergente y luego liberar el ADN de sus proteínas protectoras (histonas) usando una enzima que degrada proteínas, llamada proteasa (que es, ni más ni menos que el ablandador de carne marca Accent). Entonces, al romper la pared celular, la membrana celular y nuclear, los estudiantes lograron aislar los ácidos nucleicos.

A continuación, cogieron el lisado resultante (el líquido que sobra de la degradación del germen de trigo y que contiene células) y le agregaron etanol al 70% y muy frío. Esto hizo posible que el ADN se visualizara entre los bordes de la solución acuosa y el etanol. La adición de etanol al lisado de células permite que los ácidos nucleicos se visualicen sin la necesidad de usar un microscopio. Esta actividad involucra varios pasos distintos y permitió enfatizar la importancia de seguir instrucciones de manera cuidadosa. Los jóvenes científicos fueron recompensados por su diligencia: ¡lograron observar ADN en sus tubos de ensayo!

 

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Author

Lauren Koppel

Lauren earned a Bachelor’s degree with a double major of Biology and Psychology from Clark University, and a Master of Education from the Harvard Graduate School of Education. During her undergraduate years, she worked in a evolutionary neurobiology lab that studied the neural development of annelids (marine worms), with a focus on the sox family of genes. Lauren loves learning about how the world works (including everything from biology to chemistry to engineering), and is passionate about sharing that knowledge and enthusiasm with others. In the past, she has interned at the Museum of Science, where she educated learners of all ages through hands-on activities, games, and experiments. Other science education organizations with which Lauren has worked include The People’s Science, EurekaFest, and Eureka! of Girls Inc. of Worcester. Currently she lives in Boston, where devotes her free time to playing Quidditch, reading sci-fi novels, playing her ukulele, and enjoying all the culinary delights the city has to offer.

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