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Screening - Thermofluor Screens

The Thermofluor Screens JBScreen FUNDAMENT and JBScreen SPECIFIC allow identification of protein-stabilizing buffer conditions which is pivotal for protein purification, characterization and crystallization.
Undesired overlay of screening of interdependent variables is prevented by strictly categorizing stability screening of proteins into

1. FUNDAMENTAL factors that influence the whole protein molecule (pH and ionic strength)

2. SPECIFIC factors that affect energetically important hot spots on the protein (substrates and their analogs, cations, anions, ...)

The protein’s melting temperature (Tm) is used as reporter for protein stability and determined by a thermal shift assay (96-well plate format) monitoring the unfolding of a protein in a temperature-dependent manner. The higher the Tm, the higher is the thermostability of the protein in that specific environment.

JBScreen Thermofluor FUNDAMENT and SPECIFIC are provided in a deep-well block at 0.5 ml each, which allows a flexible application of this alternative approach.

Example: Stabilizing effects on α-Chymotrypsinogen A are directly correlated with crystallizability

α-Chymotrypsinogen A was applied in JBScreen Thermofluor FUNDAMENT and SPECIFIC.
Stabilizing conditions (high ionic strength, neutral pH, CaCl2 & FeCl3) were combined without further optimization. A crystallization screen was set up:

  • without any specific ion
  • with 20 mM CaCl2
  • with 10 mM FeCl3

Crystal growth was promoted by the stabilizing specific ions CaCl2 & FeCl3 from JBScreen Thermofluor SPECIFIC.

Protein Crystallization: Simply grab the needle from the haystack

Talk held at HEC19 in Warberg, September 29th, 2016



  • Ericsson et al. (2006) Thermofluor-based high-throughput stability optimization of proteins for structural studies. Anal. Biochem. 357(2):289.
  • Reinhard et al. (2013) Optimization of protein buffer cocktails using Thermofluor. Acta Cryst. F 69:209.
  • Niesen et al. (2007) The use of differential scanning fluorimetry to detect ligand interactions that promote protein stability. Nat. Protoc. 2(9):2212.
  • http://www.rcsb.org/pdb/home/home.do