THE MACRO FLOW PLANKTOMETER - A NEW DEVICE FOR VOLUME AND FLUORESCENCE ANALYSIS OF MACRO PLANKTON INCLUDING TRIGGERED VIDEO IMAGING IN FLOW

A newly developed macro flow planktometer is described for measuring p lankton organisms with a size of 100-2,000 mu m by the flow principle in timesaving and noncontact fashion. Based on the method of changes i n electric resistance (Coulter principle), the device allows determina tion of the body volume of Living organisms in their natural medium (f resh or seawater) at a measuring rate of up to 50 organisms per second . Simultaneous, laser-excited fluorescence measurement permits quantit ative detection of fluorescent substances within the organisms. Contro lled by the multiparametric measurement, video images of organisms of particular interest can be taken in the flow chamber using a strobosco pic imaging system. Valuable morphological information on the material under test is thus available in addition to the analytical measuremen t. Data acquisition and imaging, the total system control, and the fas t data evaluation are performed with an IBM-AT compatible computer usi ng an extensive software package. The easy-to-handle desktop unit can be used both in land laboratories and on ships. The modular structure of the system permits any desired combination of individual components to adapt it to various requirements. The operability of this new meas uring system is demonstrated by several applications. (C) 1994 Wiley-L iss, Inc.