O. Niwa et al., Continuous measurement of histamine from rat basophilic leukemia cells (RBL-2H3) with an on-line sensor using histamine oxidase, SENS ACTU-B, 67(1-2), 2000, pp. 43-51
Histamine release from rat basophilic leukemia (RBL-2H3) cells was continuo
usly measured using a histamine oxidase (HO)-immobilized on-line electroche
mical sensor. The sensor has a carbon-based electrode modified with a bilay
er of osmium-polyvinylpynidine-based gel containing horseradish peroxidase
(HRP) and BSA containing HO. The high specificity of the enzyme made the se
nsor highly selective with regards to diamines such as putrescine and cadav
erine. We obtained a low detection limit of 23 nM owing to the low operatio
n potential of the sensor (below 0 V vs. Ag/AgCl) and the high activity of
the enzyme after immobilization. Moreover, the sensor had a high conversion
efficiency. The sensor response was unaffected by 400 min of continuous hi
stamine measurement and by more than 2 weeks of storage in a refrigerator.
We combined the histamine sensor with a microdialysis (MD) sampling probe a
nd used it to measure the histamine concentration of RBL-2H3 cells stimulat
ed with dinitrophenylated bovine serum albumin (DNP-BSA) after incubation w
ith IgE. We also fabricated a small volume histamine sensor by the microfab
rication technique and were able to measure the histamine release from a sm
all mast cell colony in real time with the sensor by drawing the extracellu
lar solution continuously through a sampling capillary located near the cel
ls. (C) 2000 Elsevier Science S.A. All rights reserved.