- High quality hi-tech solution
to venting culture vessels.
- Fully autoclavable.
- Very hydrophobic so prevents
passage of contaminating water splashes or aerosols in humid environment.
- Sub micron particle retention
- Increase air exchange safely
enabling rapid plant growth.
- Specially toughened PTFE with polymer protective layer and adhesive ring.
- Obtain expensive clean
room air quality at a fraction of the cost by venting each culture container
to the same standards of contamination control.
- PTFE technology
asked questions and information resource as applied to Adhesive Microfiltration
Discs as supplied by TQPL.
Q. Why should
I vent my cultures?
air exchanges lead to increased plant growth in many in-vitro systems.
or reduce vitrification / glassiness / hyperhydricity.
- Remove or vent ethylene, phenolic
and other deleterious gasses
in-vitro environment leads to vigorous growth and better establishment
of plants out of culture.
- Achieve good aeration without
Q. Why should
I use PTFE?
Q. What is the pore size if
the PTFE used in Adhesive Microfiltration Discs
- The pore size and PTFE structure
is sufficiently small enough to stop the passage of mites, dust, fungi,
yeast, bacteria and other microbiological contamination agents.
Q. Can I compare the pore
size with other filter systems?
Q. Where can I find a supplier
of Membrane Filters to vent my cultures?
Q. Why choose AMD from TQPL?
- We have been using multilayered PTFE venting for over 2O years in our own plant laboratory and supplying a whole range of customers in different industries. Our AMD are made exclusive for us, to our specifications. They are not available elsewhere. Our products are superiour and we will supply at small numbers according to needs at competative prices.
Q. Why is hydrophobicity
important in the AMD ?
Q. Will moisture ingress contaminate
- Generally AMD venting
does not allow inward passage of moisture from environmental dampness,
humidity or water splashes. Although not recommended it is possible to
store AMD vented cultures for short periods of time in humid growing
areas such as greenhouses without contamination loss, such cultures should
be watched carefully as standard laboratory procedure,
Q. Can I use PTFE venting
to eliminate contamination due to mites?
- Mite infestation of cultures
can be stopped by the use of our PTFE venting systems. Mites cannot pass
through the PTFE while the adhesive ring provides a strong mite barrier.
The AMD has an especially strong and wide layer of 'miteproof' adhesive.
All non-venting points of entry for mites should be eliminated.
Q. Can I obtain technical
information about the use of AMD ?
- We supply technical information
with orders and can be contacted with specific questions about our products.
We will always try and help based on our many years of experience in PTFE
venting. Our products can be used for a range of venting uses with plant
and cell culture systems. They can also be used for non in-vitro situations.
Q. What is your experience
in PTFE venting?
- We first started using multilayered
PTFE venting systems over 20 years ago, and we believe we were the first in
the UK to introduce such technology to the commercial world of orchid
raising. We continue to use AMD's to vent cultures and achieve
optimum growth rates in the plants we produce.
Q. Why have we never heard
about Adhesive Microfiltration Discs, and PTFE venting
- This is relative new technology. We have been selling PTFE venting systems since mid 1990's though before then
we kept such good ideas to ourselves and our commercial customers!
Q. Can I obtain Adhesive Microfiltration
Discs (AMD) locally?
- We supply worldwide. We are
the only source of AMD's developed specifically for plant micropropagation
and flasking needs with the correct venting characteristics for long term
aseptic cultures. Purchasing direct from ourselves allows savings on price
and offers technical advice from within the in-vitro industry. We do not
have agents or intermediaries but supply direct from TQPL.
Q. Are all PTFE venting systems
- No, this is very apparent
as soon as you examine, compare or use our AMD. The AMD's are uniquely
laminated with a strong polymer and toughened
PTFE to withstand the rigors of commercial laboratory use. We consider
many other products to be inferior to our own which were manufactured
according to our in-vitro requirements. Our new strong AMD introduced in 2012 is a tough new breakthrough in venting for a range of industries.
Q. Are the AMD's patented
- The manufacturing process
is commercially confidential. The PTFE is also subject to manufacturing treatments
to improve filtering efficiency
Q. I have seen some PTFE vents
curl up at the edges which makes them look fragile and unsuitable and wonder
if yours do this?
- This does not occur with
our product during normal usage. Our AMD's are strengthened with a polymer layer and respond well in flex tests,
Q. How can I ensure the correct
air exchange rate?
- This is affected by many factors
including the structures of the PTFE filter, the venting hole size, along
with the volume of the culture vessel. The growing room conditions, the
air flow over the discs and the phototranspiration and growth rates of
the plants and plant type can all have an influence. In addition the use
of static or shaken cultures can determine the required air flow demands
for optimal growth. Correct balance of all these factors should be aimed
for or problems may occur. We can advise.
Q. Why do I need to optimize
air exchange for in-vitro cultures?
- Good air exchange allows any
depletion in carbon dioxide levels to be eliminated which is important
in photomixotrophic cultures (air-vented cultures with a sugar carbon
source in the media). The in-vitro environment is improved with the diffusion
of carbon dioxide and deleterious phenolic and ethylene gasses. Many plants
in-vitro are intolerant to these gasses.
- Good air exchange improves
the in-vitro environment allowing cultures to grow at maximum or optimal
growth. Culture time and plant growth needs to be optimized in many systems
for rapid turn around and competative economic considerations.
Q. Will good venting help
with establishment of plants out of culture in the nursery?
- Our experience has been that
survival of plantlets is improved when well vented and good air exchange
is achieved during culture. This may well be due to the 'hardening' effect
of evapotranspiration as plants grow photomixotrophically.
- Note - Ratcliffe
Orchids Ltd., can achieve 100% survival of Paphiopedilum plants with
no losses from flasks of seedlings vented with AMD.
Q. How many times can I use
Adhesive Microfiltration Discs?
- These AMD's are primarily
used in-vitro for single usage. This is to ensure aseptic integrity and
safety of valuable cultures. Quality control over the air exchange rate
for the life of the cultures or plants can be easily achieved by single
usage. This also overcomes problems with filter contamination load over
time which leads to reducing air flow rates. See below. The 'disposable'
price of these filters is often small compared to the value of plants.
We recommend single usage but on occasions where less valuable stock is
being grown repeated autoclaving can be tried as the customers own risk
and evaluated accordingly.
Q. What is filter contamination
- This is the entrapped debris,
particles and microorganisms removed during the process of filtration
from air or gasses passing through the filters. This increases over time
and use and is a factor of the external filtration environment. An increased
contamination load affects filtration efficiency, air flow and increases
potential contamination risk.
Q. How can I ensure the best
air filtration for my cultures?
- Single usage of AMD ensures optimal filtration efficiencies and quality control of filtration
Q. How can I stop contamination
from the air supply?
- If you ensure your containers
do not leak air or contamination and adopt AMD venting, with correct
autoclaving procedures, subsequent venting contamination can be eliminated
by the correct use of these PTFE venting systems.
Q. Why do I need to achieve
quality controlled venting?
- Uniform air exchange allows
uniform batch growth of cultures and improves the quality control of plants.
This is especially important where either rapidly growing cultures are
being grown by either liquid or solid culture batch techniques. Long-term
in-vitro cultures also need to optimize growth conditions to allow uniform
growth. Any limiting factor will become exaggerated over time.
Q. I normally use cotton wool
to vent my cultures, should I change?
- The principle disadvantages
with using cotton wool, is possible contamination risk. Liquids can leak
in both directions carrying contamination or inviting it in - even with
non-absorbent cotton wool. Uneven air flow occurs between different bungs
and flasks - according to how firmly the cotton wool has been plugged.
Good practice requires the use of hazardous chemicals and a required 'cotton
wool depth' of at least 1 inch to eliminate contaminating agents. It is
often necessary to further cover the cotton wool with foils or polythene
- Shipping in-vitro can cause
problems with rapid air inflow using cotton wool. It is quite a common problem for such flasks to contaminate a few weeks after air travel. This can also be a problem when flasks are simply shipped from laboratory to another storage area or pehaps when taken to a plant sales bench.
Q. I have seen disks stuck
to flasks that look like discoloured medical bandaged are these PTFE?
- Some orchid flaskers use medical
bandages to vent their flasks. These suffer from discolouration, and often
need to be applied both internally and externally. They are not PTFE vents,
and suffer from clogging and swelling fibers over time - leading to a
drop off in efficiency of air flow and filtration. Our PTFE vents are
Q. Will I have to drill a
hole in my containers before applying an AMD ?
- You will have to drill a hole,
and the diameter is critical, we can advise with orders if requested.
For a clean hole in plastic we advise the use of an electric drill with
metal cutting drill bit. Information sheets provided give details of the
Q. Can AMD be used with rubber
bungs or Kimax rubber closure lids?
- Yes, we can advise, and by
this means risks of moisture ingress can be eliminated and quality controlled
hydrophobic venting adopted.
Q. What other uses can PTFE
venting discs be put to?
- Our discs can be used for
a variety of different uses other than in-vitro venting. There are many
industries where sub-micron particle retention is required to eliminate
particles from air or gas passage They can also be used to provide a route
to equalize pressures. Their hydrophobic nature means they have uses with
moisture sensitive equipment. The unique use of an adhesive makes these
discs very versatile.
- If you wish to discuss this
please contact us and we are only too willing to advise if we can.
Q. Can Adhesive Microfiltration
Discs be used for carbon dioxide enrichment studies?
- The growth of plants by photoautotrophic
micropropagation and a high carbon dioxide concentration is a developing
field. These provide an alternative to fragile gas-permeable films and
at present are being evaluated by the leading scientists in the field
at Chiba University, Japan. We have supplied leading teams around the world.
Q. Are there alternative methods
than an autoclave for sterilizing the AMD?
- AMD discs can be
sterilized using gamma radiation, a suitable ultraviolet source or ethylene
oxide gas sterilant. It is important to ensure all the internal microfibrils are sterile.
- They cannot be sterilised by microwave or by chlorine bleach
Q. Can I ship my cultures
by air carrier without contamination?
- Yes, AMD discs provide a safe way to vent cultures for air travel, where pressure
changes make it vitally important that a reliable system is used. This
is especially important where using a non-rigid container or flask. Without
venting such containers will distort and blow the lids off. For flexible
containers we recommend the AMD to ensure the best integrity and arrival
of cultures intact and aseptic integrity ensured.
- Our Plant Culture Containers
weigh only 19gms so provide an excellent option for international shipping
and with AMD fitted have proved completely safe for transporting plants
in-vitro around the world. We have no contamination losses from such transport
systems. There is no need for any additional taping or sealing as the
lids are snap secure.
Q. Can germplasm be stored
at reduce temperature with reduced venting?
- Experience has shown that
the AMD's can be adapted to such techniques without problems sometimes
associated with dehydration of media or drying out of plant material.
Q. Can long term cultures
such as orchids be safely vented for many months?
- Yes. PTFE venting with AMD's
is an ideal approach and has many advantages compared to conventional
venting. Our experience with this crop is that aseptic integrity is safe
and venting for periods of 18 months can readily be achieved.
Q How many times can I autoclave
PTFE discs such as the AMD?
single usage for optimal venting and quality control. However the AMD
consists of material that can be repeatedly autoclaved. PTFE,
polymer, and the adhesive are all repeatedly autoclavable. We
would not advise removing the discs between autoclaving as this will
damage the integrity of the PTFE and adhesive. We would advise to proceed
with caution if such an approach is adopted. Some of our customers report
repeated use with success.
Adhesive Microfiltration Discs to be found at Modern Venting Systems now updated - click
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