More Accurate Seed Counts
Over the last decade, LEHLE
SEEDS has focused on optimizing our growing conditions for
Arabidopsis. As a result of our efforts, our mean seed size
and weight has increased. However, increases in the seed
weight reduces the seed count per gram. Thus, the traditional
rule of thumb value of 50,000 Arabidopsis seeds per gram does not
reflect the seeds we are producing now. As such, I have
decided that our seed labels going forward will report seed counts
based on samples containing 500 or more Arabidopsis seeds.
Fred Lehle, Ph.D.
August 21, 2010
New Item -
Cat. No. DV-30 Precision Swiss Clamping Tweezers for crossing
|Cat. No. DV-30 Precision Swiss
Clamping Tweezers for Crossing Arabidopsis flowers
LEHLE SEEDS is happy to
announce that we have added a new item to our catalog - Cat. no. DV-30
is a Precision Swiss Clamping Tweezers selected by LEHLE SEEDS for crossing
Arabidopsis flowers. These unique
tweezers are made by Rubis of Switzerland, a firm internationally recognized
for their award winning designs and craftsmanship. As such,
the DV-30 is manufactured from the finest grades of stainless
steel polished to a
smooth satin finish with rough edge grooving for tweezers rigidity. Tips are
ultra-fine. Not satisfied with the best, LEHLE SEEDS
includes some simple add-ons to the basic Rubis design, for
setting tip gap limits, improved one-
handed clamping control and better on-edge handling which is our
preferred orientation for Arabidopsis flower emasculation.
for more on the DV-30.
August 21, 2010
Happened to Cat. No. DV-05 Custom Clamping Tweezers?
The DV-30 replaces our
cat. no. DV-05 Custom Clamping Tweezers which, unfortunately, are
no longer being made. The clamp of the DV-05 was designed
and made by Ernest Fullam Inc
which regrettably closed its doors this past December after 57
years (and 2 generations) in business. The
company was founded in 1953 by Ernest F.and Barbara Fullam and
focused on services and products for microscopy. Ernest F.
Fullam was a pioneer in electron microscopy in the United States, who
in 1945 published with "Rockefeller [University] biologists
Albert Caude and Keith Porter the first
electron micrograph of an intact cell" (Rockerfeller
University). Ernest was also a founding
member of the Microscopy Society of America in 1942 and was
present for its 50th anniversary meeting in 1992. Ernest's
son, Peter Fullam, took over reins of the firm in 1977 until its
recent sale to Ted Pella Inc.
We here at LEHLE SEEDS will miss the Fullam's family service and
contributions to the scientific community all these many years and
wish Peter and his family well in their future endeavors.
Fred Lehle, PhD.
July 23, 2010
Our primary fax line (1-512-388-3974) was repaired today
July 23, 2010 about 2:45 pm CST. We have resumed normal fax
service at 1-512-388-3974.
Fred Lehle, Ph.D.
March 23, 2010
Transfer Payments - Change in Policy
For the last few years, LEHLE SEEDS's
stated policy has been not to accept payment by bank wire transfers if the amount is less
than $2,500.00 USD. But due to relentless and widespread requests
for this payment method despite our objections, LEHLE SEEDS, as of
March 23, 2010, has amended its terms
to allow payment by wire transfer for a Wire Transfer Processing Fee
January 1, 2010
Documents Preparation Fee
January 1, 2010, LEHLE SEEDS has instituted a new Customs
Documentation Preparation (CDP) fee. The CDP fee will be a flat
$35 and will be applied to all orders shipped to destinations
outside the U.S. The change is necessary to correct a
long-standing imbalance inherent in our "One World"
product pricing policy. The imbalance arises because international
orders require additional customs documentation not required of
domestic orders. Hence, preparation of said customs documents
incur significant internal staffing costs, which previously have
not been properly accounted for.
August 2, 2009
ArabiSifters Available for Sale.
LEHLE SEEDS is pleased to
announce that our newly redesigned cat. no. SNS-02 ArabiSifter
floral sleeves have arrived and are ready for sale. Originally introduced here as cat. no.
SNS-01 ArabiSifter Floral Sleeves on April 3, 2007, this first
generation of ArabiSifter ran into quality control issues in the
summer of 2008. To overcome this problem, LEHLE SEEDS
literally searched the world to find a new sleeve manufacturer who
could manufacture the ArabiSifter to our custom
specifications. The search was successful and the result is
a unique floral sleeve specifically for Arabidopsis of consistent quality and
novel utility - the new cat. no. SNS-02 ArabiSifter Floral Sleeve.
|Figure 1. LEHLE SEEDS
cat. no. SNS-01 ArabiSifter floral sleeve on
our square ArabiPot (see below) growing
container. 24-day-old Columbia Col-0 Arabidopsis is
shown growing on LEHLE SEEDS cat. no. PM-25-13 PMP Growing
Medium. Our new cat. no. SNS-02 sleeves are
similar except orientation of microperforations is
lateral rows for more efficient sieving and sleeves
accommodate taller plants.
|Figure 2. Close-up edge view of
cat. no. SNS-01 ArabiSifter after being removed from mature plant
showing Arabidopsis seeds being sieved from same ArabiSifter in
which they were grown. Note how ArabiSifter retains siliques
and other plant residue while seeds easily fall through holes of
shaken ArabiSifter. In this photograph, the ArabiSifter had
only been tapped gently once or twice prior to taking the
picture so seeds could be seen both before and after
sieving. Note line of accumulated seeds still inside the
ArabiSifter. These will readily sieve through the holes
with more shaking. New cat. no. SNS-02 provides improved
performance over cat. no. SNS-01 sleeves with greatly
increased uniformity in shape and size of
SEEDS has redesigned the new SNS-02 ArabiSifter in several
ways. First, we have changed the pattern of
microperforations to that of repeated, single file rows to
increase the speed and efficiency of seed sieving. Second,
we interspersed between the rows of microperforations,
non-perforated strips to align the seeds during sieving and
improve the overall sleeve strength as well as its light
transmissibility. Third, and most importantly, the
microperforations are now sized to our tolerances to ensure
consistent seed sieving. Finally, we have increased the
overall length of the new ArabiSifter sleeves by about 2 inches to
accommodate taller inflorescences. The redesigned
ArabiSifter is so improved that we have assigned it the new
catalog no. of SNS-02.
Healthy Arabidopsis plants produce lots of flowers. As a
result, flowers in nearby pots will readily entangle. One
way to prevent flower entanglement is to enclose the flowers of
each plant within a long clear plastic tube. A good
solution, but air-circulation is sometimes a problem and the tube
must be removed to thresh and clean the seeds. Harvest can be
quite tedious and time-consuming if a single hand sieve must be
cleaned completely after each plant is harvested.
LEHLE SEEDS is now offering
the 2nd generation in its new innovation for flower
containment and seed harvest of our own design. We call it
the ArabiSifter and have assigned it cat. no. SNS-02. Early users have reported to us that they really like
using the ArabiSifter. They also like the fact that the
ArabiSifter is very affordable and makes seed cleaning during
harvest much more convenient, since with the ArabiSifter, the
sieve is disposable.
So what is the ArabiSifter? The ArabiSifter is simply a flared, light-weight,
transparent plastic floral sleeve that encloses an Arabidopsis
plant or plants growing in either a round or square
Similar to existing tubular enclosures, the ArabiSifter
1) provides support for your
flowers and 2) acts as a physical barrier to prevent the
flowers in one pot from entangling with
those of another (Figure 1).
The ArabiSifter, however, goes a step further. First,
the unique design of the ArabiSifter
is that each
ArabiSifter is covered with thousands of small holes. Relative to a
rigid, solid-walled tube, we believe the holes in the ArabiSifter as well as its flared top will facilitate better air and moisture circulation and better heat and ethylene
dissipation in confined spaces such as in a growth room.
But the real purpose of the holes in the ArabiSifter is to
seed cleaning and save time and labor at seed harvest. The ArabiSifter accomplishes
this by serving as a disposable seed sieve as follows. The mature
plant and enclosing ArabiSifter is cut from the pot at the base,
and both open ends are stapled closed. The plant material
enclosed in the ArabiSifter is then gently shaken by hand over a
large sheet of paper. The shattered seeds fall through the holes which act
to sieve the seeds from the retained plant residue (Figure
2). Since each plant has its own disposable ArabiSifter sieve,
you save time by not having to clean and dry a permanent hand sieve
between separate harvests. If you have ever harvested a lot
of separate Arabidopsis plants, you know cleaning a hand sieve
between harvests is a major bottleneck.
As you know, rendering transgenic plant residue harmless before
disposal is essential for regulatory compliance. For its
part, the ArabiSifter simplifies this process considerably.
Simply wrap your used ArabiSifters en masse with enclosed plant
residue in folded aluminum foil and autoclave on the 10 min
"wrap" cycle. Place this in the trash and this
portion of your transgenic waste disposal problem is
complete. Compliance this convenient is spelled A-r-a-b-i-S-i-f-t-e-r.
So what are some factors affecting sieving efficiency with the
ArabiSifter? First, your plants should be mature and ready
for harvest. This means the siliques are dry, have no green
color left and readily shatter their seeds when disturbed.
Under these conditions, sieving efficiency with the
ArabiSifter is greater the gentler the shaking. More
aggressive shaking and crushing of plant residue will cause more chaff and
fines to end up in the seed fraction, just like with a metal hand sieve. Regardless of your
method or technique, one pass through the ArabiSifter will free
your seeds from the bulk of the plant residue.
The ArabiSifter is sold in a standard box
of 200 sleeves. Inside the sleevers are packed into convenient, stacks of 50 sleeves that
you tear-off one at a time. The flat dimensions are specified as
4" (10.2 cm; bottom edge) x 13.5" ( 34.3 cm; top edge) x
24" (60.9 cm; length). Before using, simply cut the bottom edge of the
ArabiSifter to fit your existing pot. Trim the top edge to
fit the height of your lighting system. The ArabiSifter fits a
wide range of both round and square plots, from a 3" (7.6 cm)
diameter round pot to our recommended square ArabiPot (shown
In September of 2011, LEHLE
SEEDS introduced the third and current generation of ArabiSifters,
cat. no. SNS-03 ArabiSifter Floral Sleeves, replacing previous
versions. SNS-03 ArabiSifters have the same design and
footprint, but are 1) made of higher quality film, 2) have much more
precise sieve holes and 3) now are manufactured here in the
cat. no. SNS-03 ArabiSifter Floral Sleeves are in stock and ready
for shipment. Call 1-512-388-3945 or fax (1-512-388-3974) your
Floral Sleeves for Arabidopsis
(economy 10 pack)
(Toll-free in USA)
March 30, 2009
Update - New Organizer Insert, New Subirrigation Tray, New Cat.
recently substantially reconfigured the ArabiPot cat.
no. PTA-10. We removed the deep open subirrigation tray and
replaced it with two new components: 1) a new low -profile
subirrigation tray of the same footprint and 2) a intermediate
flat insert that organizes the 18 ArabiPots into a convenient
array. The new subirrigation tray prevents accidental
overwatering by setting an upper limit on the amount of each
irrigation. The new insert keeps the ArabiPots neatly
organized in an 3 x 6 array, something that was needed in the
original configuration. The insert has a perforated
bottom, so irrigation added to any portion of the insert is
immediately distributed equally in the lower tray. If the
growth space is available, the 3 x 6 array can be expanded with
multiple trays (6 total) into the common 9 x 12 array. We
designate this new configuration cat. no. PTA-126, which will
consist of 126 ArabiPots, 7 organizer flat inserts and 7
subirrigation trays. With the introduction of these new
components, cat. no. PTA-10 will be retired.
rationale behind the need for the ArabiPot remains the same and is
worth repeating here. Recent research reminds us, that as the air-spaces or pores of a plant growth medium
are reduced in average
physical size, a greater proportion of medium at the bottom of the
pot becomes hypoxic and remains so longer following each
subirrigation. Water-holding capacity of a growing medium
increases as its pore size decreases. This is because water
flow is reduced as the pore size becomes smaller.
The relative low air-porosity of Arabidopsis media,
composed of perlite and peat moss with variable amounts
of vermiculite, has been rated fine (Passioura
2006). As such, Arabidopsis roots, growing in the
bottom 50-70 mm of medium, regardless of pot depth, are repeatedly
subjected to severely reduced oxygen levels following routine
2006). While it is common to grow
Arabidopsis in containers as short as 2.25" (57 mm) in
height, subirrigation under such conditions requires close
monitoring to avoid prolonged root water-logging which quickly
slows root tissue and can stunt whole Arabidopsis plant growth.
Fortunately, there is a simple solution to avoid water-logging
and hypoxia in Arabidopsis roots and that is to
grow Arabidopsis plants in a deeper pot and one holding as much
medium volume as possible. This is standard horticultural
practice for many potted plants (Pasian
In a deeper pot, a greater
percentage of the medium near the surface will always have more
pores filled with air than those in the bottom of the pot. This provides a
top region where roots can grow without the danger of
hypoxia. Given the fine porosity of common
Arabidopsis media, recent research (Passioura
that a pot would need to be at least 120 mm deep to guard against
the possibility of ever accidentally inducing complete hypoxic
conditions throughout all of a pot's growth medium.
Though counter-intuitive, square pots of the same footprint
contain significantly more volume than round pots. More
medium volume increases the number of pores which improves root
aeration. Thus, given the fine air-porosity
rating of Arabidopsis media, a taller square pot is much better
for growth than a
short round pot. The ArabiPot is a 3.5" x
3.5" (89 x 89 mm) square pot which is a full 5" (127 mm)
The ArabiPot works with ARASYSTEM Aracons as well as our
cat. no. SNS-03 ArabiSifter floral sleeves.
We recommend using the ArabiPot with either our cat. no. PM-15-13
AIS or cat. no. PM-25-13 PMP growing media for best results.
A single ArabiPot holds about 0.66 L of growing medium. A
box of PM-15-13 (or PM-25-13, 13 dry gallons each) will fill about
74 individual ArabiPots or 4 trays of ArabiPots (18 ArabiPots per
tray). Thus, you will need 2 boxes of either growing
media to fill the 126 ArabiPots of cat. no. PTA-126.
CC (1997) The Ohio State University Fact Sheet HYG-1251-97
Physical Characteristics of Growing Mixes. OSU Horticulture and
Crop Science http://tinyurl.com/2cehv8
Passioura JB (2006) The perils of pot
experiments. Func. Plant Biol.33:1075-1079
ArabiPots, Organizer Flats & Subirrigation Trays for Arabidopsis
includes 126 pots, 7 Organizer Inserts & 7 low-porfile subirrigation trays
To place an order
(Toll-free in USA)