1. What is Antibody Molecular Weight?

Antibody molecular weight refers to the mass of an antibody molecule, typically measured in Daltons (Da). Different antibody classes (IgG, IgM, IgA, IgD, IgE) have different molecular weights due to their structural differences.

2. How Does the Calculator Work?

The calculator uses standard molecular weights for different antibody classes:

Where:

• IgG — ~150,000 Da
• IgM — ~900,000 Da
• IgA — ~160,000 Da
• IgD — ~180,000 Da
• IgE — ~190,000 Da

Explanation: These values are approximations as actual molecular weight can vary slightly depending on specific antibody sequences and post-translational modifications.

3. Importance of Molecular Weight

Details: Knowing antibody molecular weight is crucial for laboratory techniques like SDS-PAGE, size-exclusion chromatography, and calculating molar concentrations for experiments.

4. Using the Calculator

Tips: Simply select the antibody type from the dropdown menu and click calculate to get the approximate molecular weight.

5. Frequently Asked Questions (FAQ)

Q1: Why are these molecular weights approximate?
A: Exact molecular weights can vary slightly due to differences in amino acid sequences, glycosylation patterns, and other post-translational modifications.

Q2: What's the difference between IgG and IgM molecular weights?
A: IgG is a monomer (~150 kDa) while IgM forms a pentamer (~900 kDa), explaining the significant difference in size.

Q3: How does molecular weight affect antibody function?
A: Larger antibodies like IgM are better at agglutination but don't diffuse as easily as smaller antibodies like IgG.

Q4: Can this calculator be used for antibody fragments?
A: No, this calculator only provides molecular weights for intact antibodies. Fab, F(ab')2, and scFv fragments have different weights.

Q5: What units are used for molecular weight?
A: The calculator uses Daltons (Da), where 1 Da is approximately the mass of one hydrogen atom.