• Home
  • Search Results
  • Sensitive detection of trypsin using liquid-crystal droplet patterns modulated by interactions between poly-L-lysine and a phospholipid monolayer.

Sensitive detection of trypsin using liquid-crystal droplet patterns modulated by interactions between poly-L-lysine and a phospholipid monolayer.

Chemphyschem : a European journal of chemical physics and physical chemistry (2014-05-23)
Minmin Zhang, Chang-Hyun Jang
ABSTRACT

Liquid-crystal (LC) droplet patterns are formed on a glass slide by evaporating a solution of nematic LC dissolved in heptane. In the presence of an anionic phospholipid, 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DOPG), the LCs display a dark cross pattern, indicating a homeotropic orientation. When LC patterns are incubated with an aqueous mixture of DOPG and poly-L-lysine (PLL), there is a transition in the LC pattern from a dark cross to a bright fan shape due to the electrostatic interaction between DOPG and PLL. Known to catalyze the hydrolysis of PLL into oligopeptide fragments, trypsin is preincubated with PLL, significantly decreasing the interactions between PLL and DOPG. LCs adopt a perpendicular orientation at the water-LC droplet interface, which gives rise to a dark cross pattern. This optical response of LC droplets is the basis for a quick and sensitive biosensor for trypsin.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Sodium chloride, BioPerformance Certified, ≥99% (titration), suitable for insect cell culture, suitable for plant cell culture
Supelco
Hydrogen peroxide solution, 30 % (w/w), for ultratrace analysis
Supelco
Sodium chloride, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Sodium chloride solution, 5 M
Sigma-Aldrich
Sodium chloride solution, 5 M in H2O, BioReagent, for molecular biology, suitable for cell culture
Sigma-Aldrich
Sodium chloride, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture, ≥99%
Sigma-Aldrich
Sodium chloride, tablet
Sigma-Aldrich
Sodium chloride, meets analytical specification of Ph. Eur., BP, USP, 99.0-100.5%
Sigma-Aldrich
Hydrogen peroxide solution, 30 % (w/w) in H2O, contains stabilizer
Sigma-Aldrich
Sodium chloride solution, 0.9% in water, BioXtra, suitable for cell culture
Sigma-Aldrich
Sodium chloride, BioXtra, ≥99.5% (AT)
Sigma-Aldrich
Sodium chloride, for molecular biology, DNase, RNase, and protease, none detected, ≥99% (titration)
Sigma-Aldrich
Sodium chloride solution, 0.85%
Sigma-Aldrich
Sulfuric acid, 99.999%
Sigma-Aldrich
Sodium chloride, random crystals, optical grade, 99.9% trace metals basis
Sigma-Aldrich
Sodium chloride-35Cl, 99 atom % 35Cl
Sigma-Aldrich
Sodium chloride, 99.999% trace metals basis
Sigma-Aldrich
Hydrogen peroxide solution, contains potassium stannate as inhibitor, 30-32 wt. % in water, semiconductor grade, 99.999% trace metals basis
Sigma-Aldrich
Sodium chloride, AnhydroBeads, −10 mesh, 99.99% trace metals basis
Sigma-Aldrich
Sodium chloride, AnhydroBeads, −10 mesh, 99.999% trace metals basis
Millipore
Hydrogen peroxide solution, 3%, suitable for microbiology
Sigma-Aldrich
Hydrogen peroxide solution, tested according to Ph. Eur.
Sigma-Aldrich
Sodium chloride, BioUltra, for molecular biology, ≥99.5% (AT)
Sigma-Aldrich
Sodium chloride solution, BioUltra, for molecular biology, ~5 M in H2O
Sigma-Aldrich
Sodium chloride, tested according to Ph. Eur.
Supelco
Sulfuric acid, for the determination of nitrogen, ≥97.0%
Supelco
Sodium chloride, certified reference material for titrimetry, certified by BAM, ≥99.5%
Sigma-Aldrich
Hydrogen peroxide solution, 34.5-36.5%
Supelco
Hydrogen peroxide solution, ≥30%, for trace analysis
SAFC
Sodium chloride solution, 5 M