Multi-point Inoculator

The HMI-60&24 multipoint inoculator (HAUK Technology & Development Co., Ltd), has dramatically increased the efficiency of agar dilution MIC determinations conducted in our laboratory. It has addressed our requirement to test multiple antimicrobial agents against large panels of anaerobic bacteria while reducing the number of MIC plate series that must be prepared for each agent. The efficient design of the HMI-60&24 inoculator head accommodates 60 pins, allowing this number of bacterial strains to be accurately deposited onto a standard 90 mm agar plate. Although this necessitates inoculum sites that are tightly spaced, a special treatment applied by the manufacturer to the steel pins eliminates dripping of the inocula and produces well defined inoculum sites on various agar formulations. In our work we use supplemented Brucella Blood Agar, Fastidious Anaerobe Agar and supplemented Brain Heart Infusion Agar - it works well with each of these. The inoculum container for the HAUK instrument is a standard 96 well microtitre plate, which is especially convenient to load and is disposable, reducing maintenance and setup time. The treated stainless steel inoculator heads and pins are easily cleaned and sterilized. The rotating design of the HMI-60&24 inoculator provides a further improvement in efficiency. The platform accommodates the inoculum tray and two agar plates, which are inoculated sequentially using bidirectional rotation of the platform. Thus, the first plate can be removed and replaced while the second is being inoculated, allowing continuous operation until the complete series of MIC plates has been inoculated without the need to stop the instrument. Two speeds can be selected facilitate this way of working. Alternatively, each pair of plates can be inoculated and the instrument paused (via the touchscreen or foot switch) while the two plates are replaced. One of the key requirements for our application was an inoculator that could be accommodated inside an anaerobic workstation and operate within its internal atmosphere (temperature 37°C and relative humidity up to 80%). HAUK Technology & Development Co. was able to guarantee that the HMI-60&24 instrument would function reliably under these conditions, and it has done so for several months so far. The shape of the inoculator makes efficient use of space within the anaerobic workstation because it is relatively tall and deep, while the width is minimized: this leaves the maximum possible working space for other anaerobic work and plate incubation. Finally, it is important to note that that the price of the HAUK inoculator is significantly less that other currently available multipoint inoculators (none of which offer 60 pin inoculation capability).

Review Date: 10 Nov 2025 | HAUK Technology