Controlled Rate Freezers are necessary for the accurate, repeatable process of reducing temperature in accordance with a given or programmed protocol. Whilst many biological samples may be stored via mechanical freezers or freeze drying, viability for a large proportion is optimised, or ensured, by storage at liquid nitrogen temperatures.
The process of freezing down samples using cryo protectants can be a complex one. Rate of cooling affects protectant concentration which in turn may affect the cells beings frozen. The aim of good cryo-preservation is to ensure maximum viability of samples.
Planer programmable freezers have:
• Class 11a Medical Device compliance options
• Horizontal or vertical freezing option
• PID engine based controllers
• Maximum temperature control and range
• Temperature accuracy using Class A Platinum Resistance Thermometers
• Independent controllers - helps safeguard operation and protocols in power outs or downs
PETRISENSE™ - A single sensor for monitoring of pH or CO2
Benefit from the protection of the PetriSense™ Fixed alarm and monitoring unit, with its 35 mm petri dish sized sensor, in a variety of laboratory equipment.
Monitor pH and/or CO2 in a variety of equipment with the latest monitoring innovation from Planer. This new sensor provides accurate measurements in benchtop incubators, environmental chambers and large incubators.
The PetriSense™ pH and CO2 sensor from Planer allows users to both measure CO2 and monitor the pH of established culture systems. The small sensor size (equivalent to a 35mm petri dish) combined with an ultra thin ribbon cable allows convenient measurement of CO2 levels inside equipment, which previously has been difficult to achieve. Using the established relationship between CO2 and pH, combined with the characteristics of both the culture media and growth conditions, accurate pH values can be monitored, continuously, without the expense or inconvenience of traditional methods.
Available as a fixed point monitor and alarm or a portable validation device, the PetriSense™ pH/CO2 sensor provides flexibility and innovation to ensure optimal growth conditions.
• Validate any incubator for optimum culture conditions
• Cost effective solution compared to standard CO2 sensors
• Easy to install
• Monitor and alarm of CO2 or pH for rapid notification of potentially damaging changes in culture environment
• Single portable validation unit or fixed alarm models
• Connectable to existing alarm / monitoring system
• Small 35mm petri dish sized sensor
• Auditable data for regulatory compliance
Liquid Nitrogen Safety
All the recent news surrounding the dangers involved with use of liquid nitrogen are a salutary reminder that any facility using this should carefully consider its responsibilities to reduce the risk, both to employees and clients. The growth in social use of liquid nitrogen - in cocktails for example - increases the need to underline the awareness of the dangers involved.
In 2008 Tomlinson & Morroll, surveyed UK ART labs and concluded that the number of incidents involving liquid nitrogen was higher than realised and that training and awareness of risks in cryostores were generally lacking. In the UK, licensing conditions now require clinics to have suitable monitoring, alarms and procedures in place to deal with problems such as dewar failure and/or major spills. This regulatory requirement means the labs must consider and address the risks.
Good Practice in IVF Labs
The most recent ESHRE Revised Guidelines for Good Practice in IVF Laboratories (2015) gives some guidance. Leaving aside any regulatory stipulations, we would always recommend the following:
• Visible and audible alarms inside and at the entrance of the cryostorage area linked to oxygen depletion monitors that are placed around waist height; this allows everyone to know whether the room is safe to enter and signage should make clear that nobody should enter when alarms are activated.
• Manual filling of tanks should never be done by one person working alone.
• In the event of an out-of-hours alarm, an appropriately trained member of the lab team should attend to investigate and/or remedy any incident without putting themselves at risk.
• When attending alarm calls, the team member should not attend alone; for example, we arranged a member of the hospital security team to meet the staff member to escort them to the lab and ensure they were safe.
The British Compressed Gases Association also publishes a guide to using the commonly employed dewars up to 50 litres which gives some very useful advice and information.