To determine the isoelectric point of a protein, first establish that a gel:
(a) Contains a denaturing detergent that can distribute uniform negative charges over the protein’s surface.
(b) Exhibits a stable pH gradient when ampholytes become distributed in an electric field.
(c) Is washed with an antibody specific to the protein of interest.
(d) Neutralizes all ionic groups on a protein by titrating them with strong bases.
The correct answer is:
(b) Exhibits a stable pH gradient when ampholytes become distributed in an electric field.
Explanation:
To determine the isoelectric point (pI) of a protein, isoelectric focusing (IEF) is used. IEF relies on a stable pH gradient created by ampholytes (small charged molecules) in an electric field.
- Proteins migrate within the gradient until they reach their isoelectric point (pI), where their net charge becomes zero and movement stops.
- (a) Incorrect: SDS is used in SDS-PAGE, not IEF. It denatures proteins and applies a uniform negative charge, making pI determination impossible.
- (c) Incorrect: Washing with antibodies is a step in Western blotting, not isoelectric focusing.
- (d) Incorrect: Titrating ionic groups with strong bases does not determine pI; instead, proteins naturally stop moving at their pI in a stable pH gradient.



32 Comments
Shreeji Charan
March 1, 2025🙋♀️
Prami Masih
March 4, 2025👍👍
Anurag Giri
August 14, 2025Ans b Exhibits a stable pH gradient when ampholytes become distributed in an electric field
Aman Choudhary
August 14, 2025Option B is correct
for determination of pi we need Ph gradient to stabilize the protein
Karishma Don
August 14, 2025ampholytes creates a stable ph gradient in electric field
Khushi Agarwal
August 14, 2025Option b is correct answer
Exhibits a stable pH gradient when ampholytes become distributed in an electric field.
Mansukh Kapoor
August 14, 2025The correct answer is option 2nd
Exhibits the stable pH gradient when ampholytes become disturbed in an electric field because at a point they stops migrating due to the isoelectric point
Dipti Sharma
August 14, 2025(b) Exhibits a stable pH gradient when ampholytes become distributed in an electric field.
Mohd juber Ali
August 14, 2025Option (2) is right
Exhibit the stable pH gradient when ampholytes become disturbed
In low pH (+ve charge) protein move toward cathode electrod in pH strip (horizontal gel)
pH = PI (static) neutral
Sneha Kumawat
August 14, 2025The correct answer is B, exhibits a stable pH gradient when ampholytes become distributed in an electric field
Priya khandal
August 14, 2025B is right
shruti sharma
August 16, 2025b is right
Aafreen
August 17, 2025Ans- b
Proteins migrate within the gradient until they reach their isoelectric point (pI), where their net charge becomes zero and movement stops
Avni
August 17, 2025(b) is correct
Bharti Yadav
August 24, 2025Exhibits a stable pH gradient when ampholytes become distributed in an electric field.
MOHIT AKHAND
August 24, 2025Done sir ✅
Priyanka Choudhary
August 24, 2025Answer b is correct answer,Exhibits a stable pH gradient when ampholytes become distributed in an electric field
Priya dhakad
August 24, 2025Exhibits a stable pH gradient when ampholytes become distributed in an electric field. option b is correct.
Bhavana kankhedia
August 24, 2025exhibits a stable pH gradient when ampholytes become distributed in an electric field.
Sonam Saini
August 24, 2025Option B is right
Anjali
August 24, 2025Ans is b
Sakshi
August 24, 2025Option b is correct
Exhibits a stable pH gradient when ampholytes become distributed in an electric field.
Ankita Pareek
August 24, 2025Exhibit a stable ph gradient when amhpholytes become distributed in an electric field
Falguni Prakash
August 24, 20252
sakshi khatri
August 25, 2025done
Pratibha Jain
August 30, 2025The correct answer is option (b)
Exhibits a stable pH gradient when ampholytes become distributed in an electric field.
Shriyanshi verma
August 30, 2025Ans b Exhibits a stable pH gradient when ampholytes become distributed in an electric field
Sheikh Aleen
August 30, 2025Exhibits a stable pH gradient when ampholytes become distributed in an electric field.
Patel Radha
August 30, 2025Done
Gayatri Nama
August 30, 2025To determine the isoelectric point (PI) of a protein isoelectric focusing (IEF) is used . IEF relies on a stable pH gradient created by ampholytes electric field .
Protein migrate with in the gradient untill they reach their isoelectric point ( PI) , where their net charge becomes zero and movement stops .
Shobha Kanwar
August 31, 2025Option b is correct answer
Exhibits a stable pH gradient when ampholytes become distributed in an electric field
Aakansha sharma Sharma
October 1, 2025The correct answer is:
(b) Exhibits a stable pH gradient when ampholytes become distributed in an electric field.