HOME / TECHNOLOGIES /

Light Scattering

For information on access fees, policies and getting started at the CMI, see the CMI Access Page.

The CMI offers Training/Access on SEC-MALS and DLS instruments and Data Collection Services.  

Size exclusion chromatography with multi-angle static light scattering (SEC-MALS) is used to accurately measure weight-averaged masses (Mw) of macromolecules in solution by measure the intensity of scattered light of a sample as it elutes from an SEC column.  

Dynamic Light Scattering (DLS) measures the time-dependent fluctuations in scattered light. These fluctuations are directly related to rate of diffusion of the molecule through the solvent, and can be used to measure hydrodynamic radius (Rh) of the particles in solution. ​​​​​​

Mass Photometry (MP) is a single-particle light scattering method used to measure mass of macromolecules in solution, >30 KDa and for which standards with a shared refractive index are known (e.g. Protein or DNA).

See also: molecular properties, Light Scattering

Light Scattering Services Overview

In addition to instrument training, the CMI is now offering basic Light Scattering Data Collection services, including SEC-MALS and DLS.

Light Scattering Data Collection Services

SEC-MALS Service Overview

Size-exclusion Chromatography with Multi-Angle Light Scattering (SEC-MALS)

CMI SEC-MALS System: Wyatt Dawn Heleos with in-line DLS, RI UV, Agilent chromatography

Standard SEC-MALS Service

for proteins and protein complexes between 15 KDa and 1 MDa, without high molecular weight modifiers (modifiers of mass >5% total).  Prior purification by size-exclusion chromatography (SEC) is strongly recommended.  

Includes:

  • Column equilibration with your buffer (pH at or below pH 7.5) or with PBS
  • BSA Standard to test column performance and normalize detectors
  • SEC separation of your protein sample(s)
  • Basic Data analysis, including:
    • Molar Mass for each major peak
    • Hydrodynamic Radius from DLS (when light scattering signal is sufficient)

Additional Services

  • Protein Conjugate Analysis
    • required for samples with high molecular weight modifiers, such as glycosylation or detergent micelle will require additional analysis
    • requires modifier dn/dc
  • dn/dc measurements of detergent or protein samples

SEC-MALS example data - BSA

Column: Agilent AdvanceBio 300Å, 7.8 mm x 300 mm

  • Resolution: 5KDa – 1.25 MDa (17 KDa - 667 KDa for MALS)
  • pH range: 2-8.5
  • Max pressure: 150 bar

Experimental conditions

  • Buffer:  25 mM HEPES pH 7.5, 150 mM NaCl, 0.02% NaN3
  • Sample: 100 µl BSA, 2mg/ml (Pierce 23209)
  • Flowrate: 0.5 ml/min
  • Runtime: 35 min
  • Pressure: 67 bar

SEC-MALS Data -BSA

DLS Service Overview

Dynamic Light Scattering (DLS)

CMI DLS Instrument: Wyatt Dyanpro Plate Reader III

 

Standard DLS Service

For proteins and biopolymers up to 1000 nm in diameter. Includes:

  • Cumulants and Regularization fit of Hydrodynamic Radius (Rh), 1 nm - 1000 nm
  • Polydispersity Analysis

Additional Services

  • Aggregation Analysis - Small molecule
  • Buffer optimization

 

Light Scattering Data Collection Fees Accordion

Data Collection Fees Summary

Data Collection Fees

  • Limited Data Collection Services are offered. Service fees will be charged for all completed services, regardless of experimental outcome. 
  • Before submitting samples for data collection, users must approve the estimated charges and be given a date and time for sample delivery.
    • External Users will also be required to submit a PO and a signed CMI User Agreement.
  • Most CMI Data Collection Services include a setup fee plus a per-sample data collection fee. Some services include one or more replicate measurements by default in the sample fee (e.g. DLS and DSF). For others, there may be reduced-price replicate measurement fee (e.g. SEC-MALS and CD) if collected in the same dataset.

Data Collection Fee List

Light Scattering - SEC-MALS Data Collection Fees

 

Harvard
base price

Non-Harvard
(+F&A)

Commercial

Life Lab

SEC-MALS -setup

 per buffer, includes analytical column equilibration, BSA control

$425

$518.50

$1,037.00

$777.75

SEC-MALS data collection

 per sample, analytical column, 0.5 ml/min

$250

$305.00

$610.00

$457.50

SEC-MALS replicate injection

additional injection collected in the same sequence

$100 $122 $244 $183

dn/dc measurement

 per user-provided reagent

$445

$542.90

$1,085.80

$814.35

SEC PBS Buffer preparation 

 up to 1 L, filtered and degassed

$50

$61

$122

$91.50

SEC Custom Buffer preparation 

 up to 1 L, made using reagents available at the CMI (HEPES, Phosphate, NaCl, reducing agents)

$150 $183 $366 $274.50

DLS analysis - plate setup

per set, up to 48 samples

$250 $305 $610 $457.50

DLS data collection -macromolecules

per sample, in duplicate wells, 5-10 acquisitions/scan, 2 scans/well

$60

$73.20 $146.40 $109.80
         

 

Light Scattering - DLS Data Collection Fees

 

Harvard
base price

Non-Harvard (+F&A)

Commercial

Life Lab

DLS analysis - plate setup

per set, up to 48 samples

$250

$305.00

$610.00

$457.50

DLS data collection -macromolecules

per sample, in duplicate wells, 5-10 acquisitions/scan, 2 scans/well

$60

$73.20

$146.40

$109.80

Example Project Fees

 

Example project details: Light Scattering analysis project for SEC-MALS of 2 proteins in one buffer system. Project setup includes column equilibration (12+ column volumes) into user-provided buffer and a BSA control experiment.  One additional replicate injection of each sample was requested.

line item Qty Internal price External Academic price
SEC-MALS setup  1 $425 $518.50
SEC-MALS data collection 2 2x $250 2x $305.00
SEC-MALS replicate injection 2 2x $100  2x $122.00
Total   $1,125 $1372.50

 

Data Collection Services!  

In 2022, the CMI launched data collection services for assessing protein quality and sample biophysical properties.   To start a conversation about a data collection services project, please contact the CMI or send a Sample Form to cmi@hms.harvard.edu.

Required Service Forms:

  • Sample Form, for gathering sample details to aid in data collection.  You may exclude proprietary information in your preliminary form (we'll let you know if essential information is missing). 
  • Academic Services Agreement, for EXTERNAL academic data collection service users
  • OR Industry Services Agreement, for industry data collection service users