Published on 12/11/2024 by James Best

Rosalind Franklin: The DNA Detective

Hello, junior scientists! Are you ready to meet one of the most brilliant detectives in science history? Today we’re going to learn about Rosalind Franklin, who helped solve one of the biggest mysteries ever - what does DNA look like?

The Young Explorer

Rosalind was born in London in 1920, and from a very young age, she loved solving puzzles. At school, she wasn’t just good at science - she was brilliant at it! She knew by the time she was 15 that she wanted to be a scientist. That’s younger than some of you reading this!

What’s DNA?

Before we talk about Rosalind’s amazing work, let’s understand what DNA is. Imagine you’re building with LEGO. Each LEGO brick is different, but when you put them together, you can build amazing things. DNA is a bit like that - it’s the instruction manual that tells our bodies how to build everything from our hair colour to how tall we’ll grow!

The Invisible Challenge

But here’s the tricky bit - DNA is so tiny that you can’t see it with your eyes, or even with a normal microscope! So how did Rosalind study it? She used a super clever technique called X-ray crystallography.

Rosalind’s Special Camera

Think of it like taking a photo, but instead of using light, Rosalind used X-rays (the same kind doctors use to look at broken bones). When these X-rays bounced off the DNA, they made patterns on her special camera. It’s a bit like when you shine a torch through your hands to make shadow puppets on the wall!

Photo 51 - The Famous Picture

Rosalind’s most famous picture was called “Photo 51”. It might not look exciting to you - it’s just a fuzzy X pattern - but to scientists, it was like finding buried treasure! This photo showed that DNA looks like a twisted ladder, which we now call a double helix.

Did You Know?

• Rosalind had to expose her X-ray film for 100 hours to get one good picture! That’s more than 4 days!
• She wore special lab coats to protect herself from the X-rays
• She was also brilliant at studying viruses and helped create better vaccines

Try This at Home

Want to be a DNA detective like Rosalind? Try this fun experiment:

1. Get some strawberries
2. Mash them up in a plastic bag
3. Add some washing-up liquid and salt
4. Filter the mixture through a coffee filter
5. Add some cold rubbing alcohol (ask a grown-up for help!)

You’ll see stringy bits appear - that’s real DNA!

A True Science Hero

Sadly, Rosalind died very young, at just 37 years old. But her work helped scientists understand DNA better, which means doctors today can help treat lots of different illnesses. She showed us that being patient, careful, and clever can help solve even the biggest mysteries!

Your Turn to Be a Detective

Remember, every great scientist started as a curious child like you! Keep asking questions, looking closely at the world around you, and maybe one day you’ll make an amazing discovery too!

Fun Challenge: Can you make a DNA model using sweets? Try using liquorice for the sides and gummy bears for the rungs of the ladder. Don’t forget to twist it!

Written by James Best