ShmoopTube

00:03

Here’s your Shmoop du jour, brought to you by SDS-PAGE.

00:07

Once you see what you’re dealing with, you’ll just dye.

00:13

Here’s a passage about a technique used to separate proteins.

00:26

What was the primary purpose of using SDS-PAGE?

00:31

And here are the possible answers…

00:36

Sounds like we’re being asked why SDS-PAGE was used at all.

00:39

Thankfully, that was stated right there in the opening paragraph. The opening sentence, even!

00:44

Aaaand of the four options, option B is nearly that exact same sentence. Read it!

00:49

“To separate the proteins in the protein sample by size.”

00:54

Before we call it a day, however, it’s always wise to check the other answers and make sure they’re wrong.

00:59

Option A says SDS-PAGE’s purpose was to separate DNA.

01:03

There’s nothing about DNA mentioned at all in the passage. No dice there.

01:07

Option C says SDS-PAGE was used to separate proteins by their charge.

01:12

Nothing about charge in there, either. Frankly, to even suggest it is… shocking.

01:18

Option D says SDS-PAGE was used to identify known and unknown proteins by staining.

01:23

While staining does occur as part of the SDS-PAGE process,

01:26

that’s not the purpose of using SDS-PAGE.

01:31

By the way, staining can also be used to determine whether more housetraining is necessary.

01:36

But no, option B will be just fine.

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