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?

Question

BlackTom AI · Accepted Answer

Late precipitation replaces polishing chromatography but does not eliminate the obligation to demonstrate removal of the precipitating agent; in fact, removing polishing steps usually increases the need to show precipitant clearance.

Relevant knowledge points:
- "Late precipitation" refers to introducing a precipitation step near the end of downstream processing to remove impurities and potentially replace polishing chromatography.
- Chromatography polishing steps often serve both impurity clearance and removal of process additives (e.g., precipitants). Removing those steps can change the impurity and residual-agent profile.
- Regulatory expectations require demonstration of removal/clearance of process-related impurities, including any precipitant used.

Step-by-step reasoning:
1. Consider the function of polishing chromatography: it clears trace impurities and residual process reagents. If late precipitation replaces polishing, the chromatographic step that would have removed residual precipitant is absent.
2. Regulators therefore expect data showing that any residual precipitating agent is removed to acceptable levels by subsequent operations (or shown to be at safe residual levels). Without polishing, proving clearance typically requires additional studies and justification.
3. Chapter 11.4 notes that late precipitation can sometimes match or outperform conventional ion-exchange chromatography (IEX) for certain impurity removals and that it may be used to replace polishing chromatography in some processes.
4. The chapter explicitly highlights a key challenge: demonstrating downstream removal/clearance of residual precipitating agent when polishing steps are replaced.

Why the correct (NOT consistent) option is wrong:
- The statement "Late precipitation reduces the need to demonstrate precipitant clearance because polishing steps are replaced" contradicts the chapter. Removing polishing steps does not reduce, but often increases, the requirement to demonstrate precipitant clearance because the normal mechanism for removing the precipitant (polishing chromatography) is no longer present.

Why the other options are consistent:
- "Late precipitation can match or outperform conventional IEX..." — consistent: chapter reports cases where precipitation performs as well as or better than IEX for some impurities.
- "Late precipitation may be used to replace subsequent polishing chromatography operations" — consistent: one proposed role of late precipitation is to substitute for polishing steps.
- "A key challenge is proving downstream removal/clearance of residual precipitating agent" — consistent: the chapter calls out this verification as a major challenge.

Conclusion: The statement identified ("Late precipitation reduces the need to demonstrate precipitant clearance because polishing steps are replaced") is NOT consistent with Chapter 11.4, which is why it is the correct answer.

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?单项选择题

类似问题

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

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:

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.

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

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?单项选择题

类似问题

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

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:

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.

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.