salt out
C2Technical / Scientific
Definition
Meaning
to cause a dissolved substance to separate from a solution by adding salt.
to isolate or precipitate a substance, especially a protein or organic compound, from a solution by increasing the ionic strength (typically with salt), a common technique in chemistry and biochemistry.
Linguistics
Semantic Notes
A phrasal verb with a highly specific, technical meaning. It refers to a purification/separation process. Not to be confused with the idiom "salt away" (to save money).
Dialectal Variation
British vs American Usage
Differences
No significant difference in meaning or usage. The term is used identically in scientific contexts in both regions.
Connotations
Neutral, technical, process-oriented.
Frequency
Extremely low frequency in general language; used almost exclusively in chemistry, biochemistry, and related laboratory fields.
Vocabulary
Collocations
Grammar
Valency Patterns
[Subject] salts out [Object] from [Solution] (e.g., The researcher salted out the protein from the lysate).[Object] is salted out (e.g., The enzyme was salted out using ammonium sulfate).Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “None directly associated with this technical phrasal verb.”
Usage
Context Usage
Business
Not used.
Academic
Used in scientific papers, theses, and lab reports in chemistry and life sciences.
Everyday
Virtually never used.
Technical
Core term in laboratory protocols for protein purification and chemical separations.
Examples
By Part of Speech
verb
British English
- The next step is to salt out the immunoglobulin using a saturated salt solution.
- They successfully salted out the contaminating polymers.
American English
- We need to salt out the enzyme before the next purification step.
- The protocol recommends salting out the product with sodium chloride.
adverb
British English
- The protein was isolated salting-out (rare usage, typically adjectival).
American English
- The compound was purified salting-out (rare usage, typically adjectival).
adjective
British English
- The salting-out point for this protein is well-documented.
- They employed a salting-out chromatography technique.
American English
- Ammonium sulfate is a common salting-out agent.
- The salting-out effect was observed at high concentrations.
Examples
By CEFR Level
- In the lab, we added salt to the liquid to make the solid separate, or 'salt out'.
- The process of salting out is important for making some medicines.
- To purify the antibody, the researcher chose to salt it out using ammonium sulfate precipitation.
- The technique relies on the ability to salt out different proteins at specific ionic strengths.
Learning
Memory Aids
Mnemonic
Think of adding so much SALT to soup that the vegetables OUT themselves (precipitate out).
Conceptual Metaphor
SEPARATION IS FORCING OUT (Adding salt forces the target substance out of the liquid solution).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not translate as 'соль вне' (literal nonsense).
- The correct equivalent is a process described by verbs like 'высаливать' or the noun 'высаливание'.
- Confusion with 'salt away' (откладывать деньги) is a major pitfall.
Common Mistakes
- Using 'salt out' to mean 'save money' (which is 'salt away').
- Incorrect word order: 'out salt' instead of 'salt out'.
- Using it in a non-scientific context where it will not be understood.
Practice
Quiz
In which field is the term 'salt out' most commonly used?
FAQ
Frequently Asked Questions
It is a chemical process where adding a salt to a solution causes a dissolved substance (like a protein) to become insoluble and separate out as a solid.
No, they are completely different. 'Salt out' is a scientific term for separation. 'Salt away' is an idiom meaning to save or store something, especially money, for future use.
It would be very unusual and likely confusing unless you were specifically discussing a laboratory technique with someone familiar with it.
Ammonium sulfate is the most commonly used salt for salting out proteins in biochemistry due to its high solubility and effectiveness.