LabAutomation 2006 - SLAS

TP87
Stefanie Hagemann
Center for Life Science Automation Dipl.-Ing.
Rostock, Germany
stefanie.hagemann@celisca.de
Where Laboratory Technologies Emerge and Merge
Co-Author(s)
Ilka Schneider
Paul Stoll
Establishment of an Automated Enzyme-Linked Immunosorbent Assay
Enzyme – linked immunosorbend assay (ELISA) represents one of the most commonly applied methods providing a simple, rapid, safe
and cost – effective way of protein determination. Nevertheless the process suffers from being highly time consuming and requires multiple
pipetting steps as well as extensive washing procedures leading to both manpower requirements and an increased risk of errors due to
the human factor. We therefore established an automated ELISA using a robotic system. Brain-derived neurotrophic factor (BDNF) was
chosen as the protein to be measured. Blood samples from canulation of a cubital vein of voluntary healthy probands were collected into
additive – free and heparinised containers to obtain serum and plasma samples. Blood was placed at rest for 60 minutes to allow clotting
and degranulation of the thrombocytes leading to the release of BDNF from platelets to serum. Sample containers were centrifuged
at 2000 g and 10° C for 15 minutes. Serum and plasma samples were aliquoted and stored at – 80° C until measurement. For the
quantitative determination of BDNF concentrations a commercially available kit
BDNF protein was detectable in all measured samples. Serum concentrations derived from the automated assay were comparable to
those from manually operated assays. Measured serum concentrations were in good keeping with recently published data obtained from
the largest conducted study on neurotrophin concentrations 1. Automated processing of the whole assay took 6:00 hours for 1 assay plate
(40 samples in double) and 11:40 hours for 7 assay plates (280 samples in double).
TP88
Frithjof von Germar
Institut für Mikrotechnik Mainz GmbH
Mainz, Germany
germar@imm-mainz.de
Co-Author
Frank Doffing
Institut für Mikrotechnik Mainz GmbH
Extraction and Centrifugation of Proteins in a Modular Microsystem
Coeliac disease is an inflammatory disease of the upper small intestine and is the only life long nutrient-induced enteropathy. It is caused by
a gluten intolerance and the only treatment for coeliac disease is a strict gluten-free diet.
A microsystem is developed in which the extraction of gluten is performed followed by an immunoassay for the quantitative detection.
Two components of a modular microchip system are presented which perform the extraction of gluten from unprocessed and processed
food and the separation of unsolved sample from the extract.
Lab scale extraction requires vigorous mixing combined with temperatures of several 10°C. This functionality is transferred to a chip based
peristaltic pump which provides a circular mixing in a flexible silicon tube. This module is divided in two parts. One permanent component
includes the heating device and the pump and one disposable block containing a valve to switch from loading to extraction and the silicon
tube. The performance of gluten extraction is on the same level as lab scale methods.
The separation of the extract from unsolved sample is performed with an on chip centrifuge. The separation/connection of the rotating
chip from a stator chip which is necessary for the filling of the rotating chip and the connections to the other modules is provided by an
appropriate mechanical system containing springs. An electric motor is capable to accelerate the chip containing 200 µl of sample to
15000 rpm which means approx. 4500g. This is sufficient to obtain a particle free extract of gluten.
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