You run a gel after a purification experiment. This gel is shown above:

The lane that most likely represents your completed purification is lane ____________

This lane would correlate with a ____________ in specific activity.

Question

You run a gel after a purification experiment. This gel is shown above:

The lane that most likely represents your completed purification is lane ____________

This lane would correlate with a ____________ in specific activity.

BlackTom AI · Accepted Answer

A successful purification is indicated by one dominant band at the target protein’s molecular weight with most other bands removed, so lane 4 is the best candidate for the completed purification.

1) Relevant knowledge points and concepts
- SDS-PAGE separates proteins by size; purified protein appears as a single intense band at its expected molecular weight while contaminating bands diminish or disappear.
- Specific activity = activity of enzyme (or amount of target function) per total protein mass. Purification that removes non-target proteins increases specific activity because the same or greater target amount is present in less total protein.

2) Step-by-step reasoning
- Inspect lanes: lane 3 shows multiple faint bands (not pure). Lane 5 and lane 6 show many strong bands (crude or concentrated lysates with many proteins). Lane 4 shows one very strong band near ~68 kDa and very few other bands, indicating enrichment of a single protein species.
- The single major band in lane 4 implies most remaining protein mass is the target; contaminants are largely removed → this is characteristic of a completed purification.

3) Illustrative calculation (intermediate steps)
- Suppose crude sample (lane 6) contains total protein 100 units and target protein 10 units → fraction target = 10/100 = 0.10 (10%).
- After purification (lane 4) total protein might be 12 units while target remains ~10 units → fraction target = 10/12 ≈ 0.83 (83%).
- Specific activity change ≈ 0.83 / 0.10 = 8.3-fold increase (large increase).

4) Why the correct answer is correct
- Lane 4’s single dominant band shows high purity; because specific activity depends on proportion of target vs total protein, removing non-target proteins produces a large increase in specific activity.

5) Why other options are incorrect
- “4, large decrease” contradicts the visual purity in lane 4; purification increases, not decreases, specific activity.
- Lane 6 options are wrong because lane 6 still contains many protein bands (not purified); regardless of increase/decrease wording, lane 6 does not represent a completed purification.

Conclusion: The completed purification is represented by lane 4 and it would correlate with a large increase in specific activity, matching the provided answer (4, large increase).

You run a gel after a purification experiment. This gel is shown above: The lane that most likely represents your completed purification is lane This lane would correlate with a in specific activity. 单项选择题

类似问题

A UF/DF step before Protein A. Which statement is NOT correct?

In an alternative placement described in Chapter 11.4, precipitation is introduced to replace polishing steps, but it has challenges. Which statement is NOT consistent with Chapter 11.4?

Adding precipitating agent after the cells have been removed has added value because it can:

According to Chapter 11, precipitation strategy is best described as:

For maximum removal of nonspecifically bound material, the intermediate wash pH should be:

As cell-culture titers increase, which statement is NOT consistent with the passage?

A UF/DF step before Protein A. Which statement is NOT correct?

A UF/DF step before Protein A is most justified when:

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单

You run a gel after a purification experiment. This gel is shown above: The lane that most likely represents your completed purification is lane ____________ This lane would correlate with a ____________ in specific activity. 单项选择题

类似问题

A UF/DF step before Protein A. Which statement is NOT correct?

In an alternative placement described in Chapter 11.4, precipitation is introduced to replace polishing steps, but it has challenges. Which statement is NOT consistent with Chapter 11.4?

Adding precipitating agent after the cells have been removed has added value because it can:

According to Chapter 11, precipitation strategy is best described as:

For maximum removal of nonspecifically bound material, the intermediate wash pH should be:

As cell-culture titers increase, which statement is NOT consistent with the passage?

A UF/DF step before Protein A. Which statement is NOT correct?

A UF/DF step before Protein A is most justified when:

更多留学生实用工具

希望你的学习变得更简单

You run a gel after a purification experiment. This gel is shown above: The lane that most likely represents your completed purification is lane This lane would correlate with a in specific activity. 单项选择题