Laminar flow hood (again) - Do you use bunsen burner? (May/25/2008 )
Hi. I was wondering do you use bunsen burner or flame in class II laminar flow hood? I read in the book 'culture of animal cells' by Freshney that we should not use flame in the hood as this may damage the HEPA filters and causes unstable air flow (?). But i've asked my seniors and they said that they have always used flame in the hood and there have not been any problems. This was the same in my previous lab. SO is flaming neccessary in the laminar flow hood? will it cause unstable air flow and lead to contamination? I am using Class II Biohazard cabinet from Esco.
Sorry i forgot to ask another question. Is it better to pipette solution like media when transferring or aliquot to another bottle or is pouring better? Thanks for your help 
Dear Ellyphant,
Where do we begin ?
Bunsen burners were used on the bench and in laminar flow cabinets upto the mid 1980's, when class II cabinets took over. In the 1970's and 1980's GLASS culture vessels were used and FLAMED as part of ASEPTIC technique. The main reason for this was that this helped in keeping the culture environment sterile. The obvious disadvantage in using laminar flows was that there was NO OPERATOR PROTECTION.
Class II cabinets have been introduced to GIVE OPERATOR PROTECTION AS WELL AS PRODUCT PROTECTION. This means that the HEPA filter is giving STERILE air in which to work in and is protecting the operator from adventisious agents. YOU DO NOT NEED TO USE A BUNSEN BURNER. All the common Tissue culture flask's are PLASTIC these days and do not stand up to flaming.
However if you want to use a bunsen THEN the cabinet has to be KI tested with a bunsen on...... the cabinet may not pass these vital operator protection tests. As you say it may also disrupt air flow and lead to possible contamination....just the thing you want to avoid.
Pipetting or pouring....... both can be used. When you first start culturing it is advised to pipette. When you become more experienced then pour. There are advantages/disadvantages:
i) Pouring is quicker and one operation.....may reduce the chance of contamination.
ii) You use less plastic pipettes so is more economical
iii) HOWEVER it is easy to get media around the tops of the media bottles and flasks...therefore increasing the chance of contamination.
Dom will probably moan BUT this is my experience over 30 years in cell and tissue culture....and we have been very successful at it
Kindest regards
Rhombus
Thank you so much rhombus
Thank you Rhombus