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Biochemistry

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Protein Detection

BIOCHM-TYYEUC

A colleague just performed a cellular extraction to analyze protein content.

She is particularly interested in detecting a multi-subunit, transmembrane protein with a molecular weight of ~ 45kDa (holoenzyme).

Whole protein complex (left, 45 kDa) is formed by a large subunit and a secondary subunit at 5 kDa (right). BY: Tarek Mohamed - Created for Albert.io. Copyright 2016. All rights reserved

She attempted to perform electrophoresis detection assays with a standard, commercially-sourced sample of the peptide complex on four fractions from the cellular extraction protocol.

Unfortunately, her experiment did not turn out as planned (based on a previously published research study), and she seeks your advice.

Using the data provided, why was the experiment unsuccessful?

Select ALL that apply.

PAGE (TOP panels) and Western Blots (BOTTOM panels): Colleague's results (left); results from a comparable research study (right). Std = Standard sample; 1-4 = Fraction numbers; Purple boxes in the Western blots = Anti-body positive bands. BY: Tarek Mohamed - Created for Albert.io. Copyright 2016. All rights reserved

A

She likely isolated the wrong proteins.

B

Results from the research study are likely based on native PAGE.

C

The concentration of protein in their sample was too dilute to be detected properly.

D

Their antibody for the western blot was old and not active so she was unable to detect the protein complex.

E

She likely used SDS-PAGE.

F

The standard sample was ineffective.