Cheat sheet: Static and Kinetic SPR

A quick-reference guide to the two core SPR measurement modes — when to use each, what data you get, and how to interpret the results.

Main Differences

	Static	Kinetic
Use Case	Screening and possibly Apparent K_D determination	Real-time binding; determination of Quantitative K_D, k_a, k_d
Analyte types & average size	Peptides, antibodies, proteins, complexes; 10 kDa – 500 kDa	Small: haptens, peptides, antibodies, nanoparticles, vaccines; 100+ Da
No. of experiments	Up to 4 independent experiments	≥ 2 (up to 2 independent experiments per run)
Sample injection type	Manual	Semi-automated
Sample amount	> 10 µg	~10 µg
Detection methods	Western blot, ELISA, immunoprecipitation assay, isothermal calorimetry	Isothermal calorimetry, surface chemistry, isothermal titration calorimetry

Purpose: Scouting or screening prior to Kinetic SPR, yes/no binding.

Like label-free ELISA: ligand-analyte interaction depends on diffusion, concentration, and binding strength measured as Apparent K_D
Concentration determination of active analyte in complex media (e.g. crude lysate)
Quick verification of protein expression
Contact time ~ seconds to hours so slow interactions can be measured with Static SPR
Low viscosity buffers and biomolecules 10–500 kDa are recommended
Up to 4 independent experiments (4 channels) for P4 SPR device

Purpose: Sensitive, quantitative binding characterization.

Constant flow of analyte enables ligand-analyte interaction so both strength and rate of binding are measured as Quantitative K_D
Can transfer Static SPR conditions to Kinetic SPR
Due to controlled flow, Kinetic SPR can accommodate a broader range of molecule sizes (100+ Da)
Suitable for low analyte concentrations, better real-time sensitivity

Association without dissociation
End-point response units are analyzed
Like ELISA, Apparent K_D can be estimated at ½ RU max determined by concentration titration