U.S. patent application number 10/001242 was filed with the patent office on 2002-08-15 for decondenser unit.
Invention is credited to Larsen, Flemming Stig, Nielsen, Per.
Application Number | 20020108380 10/001242 |
Document ID | / |
Family ID | 27222461 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020108380 |
Kind Code |
A1 |
Nielsen, Per ; et
al. |
August 15, 2002 |
Decondenser unit
Abstract
To counteract condense dew on a transparent cover film (3)
covering each well (2) in an array of wells which forms a test
plate (1) having a lower side formed by the bottoms of the wells
(2) and an upper side formed by the upper edges of the wells (2)
onto which edges the cover film (3) is sealingly attached, the test
plate (1) is for a set time placed with its lower surface
contacting a cooling plate (5), which is by a cooling element (8)
kept at a set temperature below the room temperature, and with its
upper surface in a distance from a heating plate (4) which is by a
heating element (7) kept at a set temperature higher than the room
temperature. A control box (9), which receives feed back signals
from the cooling plate (5) and the heating plate (4), controls the
power supply of the heating and cooling elements (7, 8) to maintain
the temperatures for the heating and the cooling plates (4, 5) set
by temperature setting buttons (13 and 14).
Inventors: |
Nielsen, Per; (Ballerup,
DK) ; Larsen, Flemming Stig; (Vanlose, DK) |
Correspondence
Address: |
PATENT DEPARTMENT
SKADDEN, ARPS, SLATE, MEAGHER & FLOM LLP
FOUR TIMES SQUARE
NEW YORK
NY
10036
US
|
Family ID: |
27222461 |
Appl. No.: |
10/001242 |
Filed: |
November 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60254010 |
Dec 7, 2000 |
|
|
|
Current U.S.
Class: |
62/3.3 ;
62/3.4 |
Current CPC
Class: |
F25B 21/02 20130101;
B01L 7/00 20130101; B01L 3/50853 20130101; B01L 3/50851 20130101;
F25B 47/006 20130101 |
Class at
Publication: |
62/3.3 ;
62/3.4 |
International
Class: |
F25B 021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2000 |
DK |
PA 2000 01771 |
Claims
1. Method for counteracting condense dew on a transparent cover
film covering each well in an array of wells which forms a test
plate having a lower side formed by the bottoms of the wells and an
upper side formed by the upper edges of the wells onto which edges
the cover film is sealingly attached, characterized in that the
test plate for a set time is placed with its lower surface
contacting a cooling plate which is kept at a set temperature below
the room temperature and with its upper surface in a distance from
a heating plate kept at a set temperature higher than the room
temperature.
2. Method according to claim 1 characterised in that the cooling
plate is maintained in the temperature interval 0-10.degree. C. and
the heating plate is held in the temperature interval
50-110.degree. C., preferably 60-75.degree. C.
3. Method according to claim 1 or 2, characterised in that the time
the test plate stays between the cooling plate and the heating
plate is 1-10 minutes, preferably 4-6 minutes.
4. An apparatus for realising the method according to claim 1,
characterised in that it comprises, a cooling plate on which a test
plate can be placed, a heating plate parallel with the cooling
plate in a distance from the cooling plate which distance is larger
than the thickness of the test plate, cooling means maintaining the
cooling plate at a set temperature lower than the room temperature,
and heating means maintaining the heating plate at a set
temperature over the room temperature.
5. An apparatus according to claim 4 characterise din that the
heating means comprises an electric resistive heating element and a
heat distributing plate to obtain an even heating all over the
heating surface facing the upper side of the test plate.
6. An apparatus according to claim 4 or 5, characterised in that
the cooling plate is cooled by a Peltier element.
7. An apparatus according to any of the claims 4-6, characterised
in that means are provided for setting the temperatures of the
heating and the cooling plate, which means cooperating with feed
back signals from the cooling and the heating plate controls a
power supply so that set temperatures for the respective plates are
maintained at a set values.
8. An apparatus according to anyone of the claims 4-7 characterised
in that the cooling plate is shaped with a raised platform mating a
depression in the bottom of a test plate.
9. An apparatus according to anyone of the claims 4-8 characterised
in that fans are provided which blows room temperature air over the
cooling plate to keep this plate dew free.
Description
[0001] Method and apparatus for counteracting condense dew on a
transparent cover film covering each well in an array of wells
which forms a test plate having a lower side formed by the bottoms
of the wells and an upper side defined by the upper edges of the
wells onto which edges the cover film is sealingly attached.
[0002] In modern laboratories high numbers of chemical compounds
are currently examined for different properties, which makes them
useful for different purposes, especially for therapeutic uses. For
the examination is used test plates comprising a large number of
juxtaposed wells. In each well a compound to be examined is placed
together with a reagent, which react with the compound if this
compound has the wanted properties. The reagent are chosen so that
the reaction can be visually inspected, although this visual
inspection is mostly made by a camera which photographs the content
of the wells and produces images which can later be inspected by a
human or a machine to select the wells containing useful compounds.
In fact the visual inspection is performed by sensors receiving a
light signal from the content of the well which signal may be
immediately evaluated to decide whether the content of the
inspected well is interesting or not.
[0003] When compounds and reagent are filled in all the wells a
transparent cover film covering the wells and closing them
hermetically is glued to the surface formed by the upper edges of
the wells. This cover film prevents evaporation of the liquid in
the wells and prevents contamination of the content of the wells.
Further it prevents contamination of the inspection apparatus if
the plate is tilted sufficiently to make the liquid flow over the
edges of the wells.
[0004] Unfortunately it has appeared that water is inclined to
condense on the side of the film facing the wells as an array of
small dew pearls which makes the film over the wells appear mat and
makes the visual inspection impossible. Even when this inspection
is performed totally automatically the reading is substantially
impaired when condensation on the cower film occurs Experiments
have shown that a condensation with small droplets on the lower
side of the cover film results in a 12% reduction of the read
signal whereas larger droplets may cause a loss of 30-40% of the
signal. If the extent of condense varies from well to well, the
interpretation of the signals will be ambiguous. Blowing hot air
over the film for a while may make the condense water evaporate to
make the film transparent but the effect will only last for a time
which is too short to allow the wanted inspection of the wells. If
too hot air is blown over the film for more than just a while, the
content of the wells or the well itself or its cover film may be
damaged before an inspection can be completed. An alternating
heating and inspection makes the inspection process slow and
cumbersome and is unsuited for an automatic scanning process.
[0005] An objective of the invention therefore is to provide a
method by which condense water on a transparent cover film can be
prevented, removed and kept away for a while sufficient to perform
an automatized inspection of all the wells on a test plate before
disturbing dew formations occur.
[0006] This is obtained by method for counteracting condense dew on
a transparent cover film covering each well in an array of wells
which forms a test plate having a lower side formed by the bottoms
of the wells and an upper side formed by the upper edges of the
wells onto which edges the cover film is sealingly attached, which
method according to the invention is characterised in that the test
plate for a set time is placed with its lower surface contacting a
cooling plate which is kept at a set temperature below the room
temperature and with its upper surface in a distance from a heating
plate kept at a set temperature higher than the room
temperature.
[0007] Appropriately the cooling plate is maintained in the
temperature interval 0-10.degree. C. and the heating plate is held
in the temperature interval 50-110.degree. C. preferably in the
interval 60-75.degree. C. whereby temperatures, which may harm the
samples in the wells, the wells or their cover film, or the gluing
between well edge and film, are avoided. The time the test plate
stays between the cooling plate and the heating plate may be 1-10
minutes which has appeared to keep the covering film free from
harmful condense for 30 minutes which is sufficient for a careful
optical reading of the reactions in the individual wells.
[0008] The invention further relates to an apparatus by which the
method can be performed. Such an apparatus is characterise in that
it comprises,
[0009] a cooling plate on which a test plate can be placed,
[0010] a heating plate parallel with the cooling plate in a
distance from the cooling plate which distance is larger than the
thickness of the testplate,
[0011] cooling means maintaining the cooling plate at a set
temperature lower than the room temperature, and
[0012] heating means maintaining the heating plate at a set
temperature over the room temperature.
[0013] According to the invention the heating means may
appropriately comprise an electric resistive heating element and a
heat distributing plate to obtain an even heating all over the
heating surface facing the upper side of the test plate.
[0014] The cooling plate may be cooled by a Peltier element, which
provides solid state cooling without use of moving parts or flowing
liquid.
[0015] The apparatus may be provided with means for setting the
temperatures of the heating and the cooling plates, which means
cooperating with feed back signals from the cooling and the heating
plates controls a power supply so that a set temperature for the
respective plates is maintained at a set value. Hereby the heating
and the cooling are provided in a reproducible way.
[0016] The cooling plate is shaped with a raised platform mating a
depression in the bottom of the test plate. This way a safe
positioning of the plate on the cooling element is obtained and the
matching platform and depression ensure a good heat conductance
between the cooling plate and the test plate. The depression is
found in common used test plates as it further serves the purpose
of making the test plates suited for piling.
[0017] The space between the heating plate and the cooling plate
may be ventilated to avoid dew on the cooling plate as any liquid
on the outer side of the covered test plate is unwanted by the
succeeding handling of the test plates.
[0018] In the following the invention is explained in further
details with references to the drawing, wherein
[0019] FIG. 1 shows a photography of a test plate with condense on
the film covering the wells of the test plate,
[0020] FIG. 2 shows a photography of a test plate without condense
on the film covering the wells of the test plate,
[0021] FIG. 3 shows schematically a sectional side view of an
apparatus according to the invention with a test plate positioned
in said apparatus,
[0022] FIG. 4 shows schematically and end side view of an apparatus
according to the invention, and
[0023] FIG. 5 shows schematically a front side view of the
apparatus shown in FIG. 4.
[0024] FIG. 1 shows a test plate comprising an array of wells
wherein samples are placed and inspected through a transparent film
covering the wells to protect their content against contamination
and drying out and further ensuring that the content of the wells
are not spilt if the plate is tilted during the handling. As the
wells containing a liquid is hermetically closed by the cover film
which is glued to the edges of the partitions between the wells,
the air between the samples and the cover film will be saturated
with vapour which will condense on the cover film as small droplets
which reflects the light and makes the inspection window appear as
a white matt surface so that no precise visual inspection can be
made. The condensed droplets make the covered open end of the wells
appear as white fields in FIG. 1.
[0025] FIG. 2 shows a test plate as the one shown in FIG. 2 but
seen before liquid has condensed on the cover film. In this picture
the film over the wells remains transparent so that the well can be
looked into. This makes the areas over the wells appear as black.
The white markings in FIG. 2 originate from reflections in the
upper edges of the partitions, which separate the wells.
[0026] To avoid condensation on the film the temperature of this
film must be raised over the dew point for the vapour in the well.
This may be obtained by blowing hot air over the plate and the
cover film. However, the heat capacity of the film is rather low so
its temperature quickly returns to the dew point when the test
plate is removed from the heating station and inserted in the
inspection apparatus.
[0027] In an apparatus according to the invention and which is
schematically shown in FIG. 3 not only the temperature of the film
is raised, but further the temperature of the bottoms of the wells
and of the samples are lowered to lie below the dew point for the
vapour over the sample so that condensation rather takes place at
the bottom of the well than at the cover film. When a sufficient
temperature difference is provided it will last some time before
condensation on the film takes place, which time is sufficient to
perform the wanted inspection of the content of each well.
[0028] FIG. 3 shows schematically an apparatus for treating a test
plate in advance of inspection of the wells. The test plate 1 has
an array of wells 2 which are covered by a cover film 3, which
adheres to the edges of the wells and seals each of the wells
1.
[0029] The apparatus comprises a heating plate 4 in or on the upper
side of which an electric resistance heating element 7 is
installed, and a cooling plate 5 which is cooled by a Peltier
element 8 mounted with its cool side in contact with the cooling
plate, whereas its warm side is provided with not shown cooling
ribs. The cooling plate 5 is provided with a raised platform 6 with
oblique edges, which platform 6 mates a depression in the bottom of
the test plate so that this test plate is secured against
horizontal movements on the cooling plate 5.
[0030] A control box 9 has a power input line 10 and contains a
controlling circuit controlling the power supply through a line 11
to the heating element 7 and through a line 12 to the cooling
element 8 on the basis of temperature signals from the heating
plate 4 and from the cooling plate 5 through lines 15 and 16,
respectively, and of the settings of a pair of temperature setting
buttons 13 and 14 for the heating plate and the cooling plate,
respectively. As a further controlling feature the distance between
the cooling plate and the heating plate can be made adjustable.
[0031] FIGS. 4 and 5 shows schematically an decondensing device
with a heating plate 4 placed in a distance over a cooling plate 5
leaving a space so that a test plate may be placed on the cooling
plate 5 beneath the heating plate 4. The cooling and heating plates
are held in distance of each other by a wall 18 comprising one or
more small fans which can blow room temperature air over the
cooling plate to keep it free from dew. The heating plate is heated
by heaters build into the heating plate whereas the cooling plate 5
is cooled by a Peltier element 8 which are cooled by cooling ribs
beneath the cooling plate. Legs 19 support the whole apparatus.
[0032] The reading of the test plates is performed automatically.
The test plates made ready for reading may be stored I piles from
which they are taken by a robot an carried to the decondenser
apparatus in which they are inserted for a set time where after
they are again taken by the robot and inserted in an imager, which
automatically performs a reading of the light from the wells.
* * * * *