Question

Lactoferrin, a milk protein, is a valuable antimicrobial agent that is extracted from pasteurized, defatted milk utilizing a column containing a charged resin. This is an example of which of the following chromatographic techniques? A. Thin-layer chromatography B. Ion-exchange chromatography C. Affinity chromatography D. Size-exclusion chromatography

Short answer

B. Ion-exchange chromatography

Step-by-step solution

Identify Keywords in the Problem

Highlight key terms such as 'milk protein,' 'antimicrobial agent,' 'extracted from pasteurized, defatted milk,' and 'charged resin.' These keywords will help determine the appropriate chromatographic technique.

Review Chromatographic Techniques

Recall the definitions and mechanisms of the chromatographic techniques listed: Thin-layer chromatography, Ion-exchange chromatography, Affinity chromatography, and Size-exclusion chromatography.

Match Keywords to Techniques

Analyze the highlighted keywords: 'charged resin' suggests the separation based on charge differences, which is characteristic of Ion-exchange chromatography.

Select the Correct Answer

Since the process uses a 'charged resin' to extract the protein, Ion-exchange chromatography (B) is the correct choice.

Key concepts

chromatographic techniques

Chromatographic techniques are powerful methods used to separate, identify, and purify components within a mixture. By utilizing different principles of separation, scientists can target specific molecules based on their unique physical or chemical properties. Here are four common types of chromatography:

• Thin-layer chromatography (TLC): Utilizes a stationary phase coated on a plate. The components separate by moving at different rates as the solvent travels up the plate.
• Ion-exchange chromatography: Employs a charged resin to separate molecules based on their charge differences. This technique is especially useful for purifying proteins.
• Affinity chromatography: Uses specific interactions between a ligand and its target molecule. It's highly selective, making it excellent for isolating a single type of protein.
• Size-exclusion chromatography: Separates molecules based on their size by passing them through a porous matrix. Larger molecules elute first as they don't get trapped in the pores.

Understanding these techniques helps determine the best method for separating desired compounds in various applications.

milk protein purification

Milk protein purification is an essential process in the dairy industry and biomedical research. Milk proteins like lactoferrin possess valuable properties, making their extraction and purification critical. Here's a simplified way to understand this process:
Lactoferrin, a key milk protein, exhibits antimicrobial properties. To purify lactoferrin, scientists use specific chromatographic techniques. Ion-exchange chromatography is particularly effective due to the charged properties of lactoferrin.
The purification process generally involves the following steps:

• Preparation: Milk is pasteurized and defatted to remove unwanted fats and bacteria.
• Chromatography Setup: A column filled with charged resin is prepared, suitable for ion-exchange chromatography.
• Extraction: The milk sample is passed through the column. Lactoferrin binds to the charged resin due to its charge.
• Elution: Lactoferrin is eluted from the column by changing the ionic strength or pH of the elution buffer.

This process ensures that lactoferrin is purified efficiently, preserving its valuable antimicrobial functions.

charged resin

Charged resin is a core component in ion-exchange chromatography. How does it work, and why is it important?
Charged resins are specially designed to have either positive or negative charges. They can attract and bind molecules with opposite charges. In ion-exchange chromatography, the resin plays a critical role in separating molecules based on their charge:

• Cation-exchange resins: Contain negatively charged groups to attract positively charged molecules (cations).
• Anion-exchange resins: Contain positively charged groups to attract negatively charged molecules (anions).

The charged resin's unique properties ensure that proteins like lactoferrin can be selectively captured from a mixture. By adjusting conditions such as pH or ionic strength, bound proteins are efficiently eluted from the resin for further analysis or use.
This targeted approach maximizes purity and yield, making ion-exchange chromatography a valuable tool in biochemical research and industrial applications.