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cyclohexane
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Registered: 07/29/09
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laminar flow hood - vertical or horizontal?
#10764299 - 07/29/09 08:30 PM (14 years, 6 months ago) |
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Hi, I am new to the message board but have been cultivating for a while. I recently acquired a laminar flow hood.
It can be positioned two ways:
Vertical: The HEPA filter is directly over the workspace and it blows air down onto the surface
or
Horizontal: The HEPA filter is directly behind the workspace (as seen in RR's video on grain to grain transfer), and blows air horizontally toward the user.
Which configuration is superior?
Thanks.
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fastfred
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Registered: 05/17/04
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Loc: Dark side of the moon
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Re: laminar flow hood - vertical or horizontal? [Re: cyclohexane]
#10765153 - 07/29/09 10:49 PM (14 years, 6 months ago) |
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A horizontal configuration is superior for a number of reasons. Vertical is not a very good setup unless you're using a non-laminar flow hood.
-FF
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cyclohexane
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Registered: 07/29/09
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Re: laminar flow hood - vertical or horizontal? [Re: cyclohexane]
#10765237 - 07/29/09 11:02 PM (14 years, 6 months ago) |
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Thanks for the info. I'd have to agree, as most bio labs I've seen use horizontally positioned hoods.
I'd be very curious to know the reasons. Couldn't find anything on google about this.
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RogerRabbit
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Registered: 03/26/03
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Re: laminar flow hood - vertical or horizontal? [Re: cyclohexane]
#10765283 - 07/29/09 11:10 PM (14 years, 6 months ago) |
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If there's contaminants on your gloves, an overhead filter will blow them into your work. If the filter is behind your work and you practice good hand position as shown in the agar and grain to grain transfer videos, the contaminants will be blown back towards your body and away from your sterile media. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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solumvita
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Re: laminar flow hood - vertical or horizontal? [Re: RogerRabbit]
#10767753 - 07/30/09 11:14 AM (14 years, 6 months ago) |
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my hood is a vertical hood originally designed as a bio-flow, which is meant to protect the operator from harmful organisms like E. coli. the reason that i use it, is that I got it for free. I must say so far, my contaminants have not been from the bench but rather from my other processes.
I am not sure if the fact that it is a bio-flow is the reason the vertical configuration works for me?
-------------------- One of these days all the answers will be revealed until then we learn from each other! www.mushrush.co.za
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urbanfarmer
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Registered: 12/22/08
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Re: laminar flow hood - vertical or horizontal? [Re: solumvita]
#10773889 - 07/31/09 10:45 AM (14 years, 6 months ago) |
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I set up my horizontal flow hood on the side of the workspace, blowing across the workspace from left to right. In theory this is better as there is less chance of blowback of contams on my body onto the workspace as my torso is outside the airstream, but I haven't actually noticed a difference between the 2 orientations. Mainly I keep it this way to conserve space in my lab.
You still have to be conscious of keeping your hands downstream of cultures, though.
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RogerRabbit
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Re: laminar flow hood - vertical or horizontal? [Re: urbanfarmer]
#10775610 - 07/31/09 04:05 PM (14 years, 6 months ago) |
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Quote:
urbanfarmer said: I set up my horizontal flow hood on the side of the workspace, blowing across the workspace from left to right. In theory this is better as there is less chance of blowback of contams on my body onto the workspace as my torso is outside the airstream
Rule number 1 is NEVER open a contaminated petri dish in front of the flowhood, regardless of configuration. You don't want those spores going everywhere. If a dish is contaminated and you're trying to isolate healthy mycelium away from it, always shut off the hood just before you make the transfer, so you're working in still air, or use a glovebox instead. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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