I would like to distribute liquid agar onto petri dishes with the Varispenser. How hot can the agar be for this?
“Varispensers are measurement devices for which the guaranteed accuracy, precision or error limits only apply in a restricted temperature range of 15 – 40 °C (conforming to DIN 12650). Applications with liquids outside this temperature range can only be carried out at the user’s own risk. At higher temperatures up to 60°C the plastic materials Teflon and polypropylene will be fully chemically resistant, but mechanically they will become slightly softer. Therefore the Varispenser may only be handled with a moderate use of force. When hot agar is aspirated out of the bottle, cooling will take place in the cold Varispenser. Since agar becomes much firmer at ca. 35 °C, blockage can easily occur. In any case immediate cleaning will be required, in particular of the valve. As an alternative the Varipenser as a whole can be warmed at 60 °C before it is used. We have no data for dispensing agar at 55 °C.
