Multiple aliquot device for distributing a liquid solution into a well

The present invention is a device which allows for receiving, distributing and storing a sample into numerous aliquots of small volume without air entrapment and with retention of aliquots when the device is manipulated. The device allows for the treatment of any or all of the aliquots with the same or different reagents and/or other chemical additives. The device comprises a housing for containing a body for guiding a sample into a plurality of wells without the need for pipetting aids, without multiple manipulations, without the retention of air and for retaining sample in the wells.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a device useful for receiving, distributing and 
storing aliquots of a sample for testing or analysis and is particularly 
useful in the sampling techniques employed in clinical microbiology 
applications. 
2. Description of Related Art 
There are many analytical methods in chemistry, clinical chemistry and 
microbiology where a liquid sample is divided into more than one aliquot 
and then tested or examined Even in the case of a single analytical 
protocol, there are many instances where replicate tests may be run on 
multiple aliquots of the sample to assure reproducibility of the result. 
When undergoing analysis and characterization, aliquots of a single sample 
may be reacted with either a variety of different chemical reagents for 
analytical purposes or may be reacted with differing amounts of a single 
reagent or both. 
Many approaches exist to aid in the preparation of aliquots of a single 
sample. A common example of such a situation exists in the modern practice 
of clinical microbiology. An unidentified microorganism is routinely 
subjected to tests and procedures to determine its identity and/or pattern 
of resistance or susceptibility to destruction by a variety of 
antimicrobic chemicals. Commercial systems for such determination are 
provided by several manufacturers and typically use between 10 and 100 
small aliquots of a sample suspension of the microorganism undergoing 
analysis. These systems require a variety of sterile vessels and pipetting 
aids for adequate filling when small physical amounts of aliquots are 
required. Therefore a need exists for a device and method for the 
preparation of sample aliquots that obviates the requirement for a variety 
of sterile vessels and pipetting aids. 
A number of devices and containers are commercially available for the 
preparation of samples for analysis. For in vitro tests, disposable, multi 
compartmental containers are provided by manufacturers in complete reagent 
kits. Immunoassays, which include the screening of blood samples for virus 
antibodies (e.g., the HIV or Hepatitis B virus), are commonly carried out 
in 96 well micro titration trays supplied precoated with appropriate 
reagents as part of a kit. Specialized equipment used in the preparation 
of samples for analysis is described in U.S. Pat. Nos. 4,761,378; 
4,496,657; 4,493,896; 4,342,407; 3,826,717; 4,154,795 and 4,200,613. 
Pipetting devices for inoculation of multi compartmental containers include 
the SCEPTORPETTE.RTM. System (trademark of Becton Dickinson and Company) 
sold by Becton Dickinson Microbiology Systems, Towson, MD and the device 
illustrated in U.S. Pat. No. 4,532,805. 
In clinical microbiology, there are a number of devices and containers 
available, having a plurality of small reaction chambers. Such devices 
include the SCEPTOR.RTM. Bacterial MIC and ID testing system (trademark of 
Becton Dickinson and Company) sold by Becton Dickinson Diagnostic 
Instrument Systems, Towson, MD, MINITED.TM. Systems (trademark of Becton 
Dickinson and Company) sold by Becton Dickinson Microbiology Systems, 
Cockeysville, MD and the API20E.RTM. Identification Strip (trademark of 
Sherwood Medical) sold by Analytab Products, Division of Sherwood Medical, 
Plainview, NY. 
Devices for manipulating liquid samples containing microorganisms for use 
with multi welled containers are described in U.S. Pat. Nos. 4,548,245; 
4,565,100; 4,239,853; 4,235,971; and 4,076,592. 
Automated devices for microorganism identification and drug susceptibility 
testing include the commercially available VITEK.TM. system (trademark of 
Vitek Systems, Inc.) sold by Vitek Systems, Inc., Hazelwood, MO and the 
devices illustrated in U.S. Pat. Nos. 3,957,583; 4,018,652; 4,116,775 and 
4,207,394. 
U.S. Pat. No. 4,806,316 to Johnson, et. al. describes a device for use in 
exposing a sample to be tested to one or more test reactants. The Johnson 
et al. device comprises a docking port, a filling manifold, a vent control 
system and a filling channel. A specific feature of the device is that it 
uses complex flow paths for liquid and air. 
A device comprising a planar surface with projections which align with the 
wells of a standard-type 96 well tissue culture plate is known in the art 
as shown in U.S. Pat. No. 4,483,925 to Noack. The projections used in 
Noack are of an absorbent nature and are used to control the removal of 
liquid from the wells. 
A commercially available system, the F.A.S.T..TM. Immunoassay System 
(trademark of Becton Dickinson and Company) by Becton Dickinson Labware 
Products, Lincoln Park, NJ, provides simultaneous addition of a reagent to 
wells of a microtiter plate, however, each well of the microtiter plate is 
previously filled by pipetting steps. 
Although there are a number of testing devices and pipetting systems 
available, there is no self-contained system available to produce small 
aliquots of a sample without entrapment of air bubbles. 
The available devices also do not allow easy error free reading of reaction 
results visually or by instruments for accurate test results, particularly 
when covered. The available devices do not have the means to provide 
aliquots of predetermined volume in a single operation and are not able to 
conveniently or accurately introduce reagents or materials into each 
separate aliquot for analysis thereof. 
Thus, a special need exists for a device and method for the convenient 
preparation of separate aliquots into efficient areas without entrapment 
of air that obviates the requirement for a variety of sterile vessels, 
pipetting aids and multiple manipulations. 
SUMMARY OF THE INVENTION 
The present invention is a device for dividing and filling sample into 
efficient aliquots without air entrapment and with retention of the 
aliquots. The device comprises a housing and a body for guiding a sample 
into a plurality of wells and for retaining the sample in the wells for 
testing and analysis. 
In a preferred embodiment of the invention, the device comprises an 
outer-base element and a sample distribution element for dividing a sample 
into pre-determined volume aliquots. 
The outer-base element preferably comprises a bottom, an inner planar 
surface, depending side walls and individual well bottoms raised from the 
inner planar surface. 
The outer-base element preferably comprises a plurality of posts projecting 
from its inner planar surface and the sample distribution element may have 
a plurality of corresponding bosses depending from its lower surface. The 
bosses engage the posts thereby securing the outer-base element to the 
sample distribution element so as to form a device. 
The sample distribution element provides for receiving, distributing, 
filling and holding sample material and comprises an upper surface, a 
lower surface, and a plurality of wells. The sample distribution element 
is associated with the outer-base element and the outer-base element 
preferably serves as the base to the sample distribution element. 
A preferred embodiment of the sample distribution element comprises a means 
for containing and/or guiding the sample sequentially over the upper 
surface of the sample distribution element. This means is a trough which 
comprises a unidirectional pathway on the upper surface of the sample 
distribution element. 
Another preferred embodiment of the sample distribution element comprises a 
means for receiving and/or distributing sample and/or for holding excess 
sample. This means is a reservoir area adjacent to the trough. 
Each well is substantially disposed between the upper and lower surface of 
the sample distribution element and transversely disposed with respect to 
the trough. Each well comprises a sidewall, a sidewall bottom surface, an 
upper mouth opening and a bottom mouth opening. The bottom mouth opening 
and the sidewall bottom surface of each well corresponds with the well 
bottoms raised from the inner planar surface of the outer-base element. 
Preferably, the upper mouth opening and the trough are substantially 
perpendicular to each other to form a substantially sharp junction. It is 
believed that the substantially sharp junction provides a means for 
separating individual aliquots from the sample. 
Preferably, the bottom mouth opening and the sidewall bottom surface are 
substantially parallel to the well bottom to form a sufficiently spaced 
means between them so that air is expelled from the well and the aliquot 
easily fills into the well. It is believed that the weight of the sample 
forces the air in the well to be pushed through the spaced means. It is 
further believed that the combination of frictional forces, hydrostatic 
pressure differential and the sample surface tension prevents the aliquot 
from leaving the well or spaced means even when the device is manipulated 
or inverted. It is also believed that the spaced means allows the diameter 
of the individual wells to be of a substantially small size and to also 
allow the aliquot to easily fill into individual small wells without any 
restriction and without the need for pipetting aids. 
The device preferably comprises a removable lid associated within the 
outer-base element and over the sample distribution element, which 
includes an upper and lower surface, depending sidewalls and a plurality 
of projections depending from its lower surface. The lid serves to prevent 
the loss of sample or aliquots from the device interior, to protect the 
contents of the device from the environment, to protect the user from the 
contents of the device should it contain a harmful or potentially harmful 
material such as a microorganism suspension and to provide a means for 
testing aliquots. 
A majority of the projections on the lid are preferably arrayed, sized and 
shaped to fit within the upper mouth opening of each well in the sample 
distribution element. 
Projections depending from the lid preferably are coated with materials to 
interact with the sample aliquot in the individual wells. Alternatively, 
one or more conduits may be on the upper surface of the lid and connected 
to one or more of the projections. Materials may be added to wells via the 
conduits after the lid has been placed over the sample distribution 
element. Materials added to the wells by the conduit and the projections 
may be in addition to materials coated on the projections. 
A preferred embodiment of the lid comprises means for absorbing excess 
sample in the reservoir of the sample distribution element which means is 
preferably a sponge or absorbent pad. 
The preferable form of the device is a rectangular shape with the wells in 
an ordered array of parallel rows. The outer-base element and the lid are 
preferably made of an optically clear plastic to facilitate viewing of the 
wells. The sample distribution element is preferably made of an opaque 
color, most preferably white, so as to provide contrast and prevent 
interference of colored sample in the wells with one another. 
The device preferably receives, divides and distributes a sample into 
individual wells that are of a substantially small volume comprising a 
small diameter and/or height for testing and/or analysis. A sample is 
provided in the reservoir of the sample distribution element and the wells 
are filled by tilting the device slightly so that the sample in the 
reservoir flows in the unidirectional pathway of the trough. Once the 
sample has traveled to the last well, the device can be tilted to make any 
excess sample travel back along the same pathway to the reservoir. This 
process assures that sample passes over the upper mouth of each well twice 
to ensure complete filling. As the sample flows from the opening of each 
well downward, air is expelled from the well through the spaced means 
between the sidewall bottom surface of the well and the well bottom. The 
substantially sharp junction of the upper mouth opening of each well and 
the trough provides a means for separating individual aliquots from the 
sample into the well. 
Sample may enter the spaced means between the sidewall bottom surface of 
the well and the well bottom after air has been expelled, and it is 
believed that the combination of frictional forces, hydrostatic pressure 
differential and the sample surface tension prevents the sample from 
flowing beyond the spaced means between the sidewall bottom surface of the 
well and the well bottom. As excess sample continues in the trough, the 
aliquot is separated from the sample by the substantially sharp junction 
of the upper mouth opening of each well and the trough. The sample easily 
fills into each well and pushes air through the spaced means. The sample 
remains in the well and in the spaced means even when the device is 
manipulated or inverted. 
The spaced means allows the aliquot to fill into individual wells of a 
small volume comprising a small diameter and/or height without any 
restriction. 
The individual wells may be coated with dried reagents that are 
reconstituted with fluid from the sample or with immobilized reagents for 
solid phase tests. More preferably, additional wet or dry reagents may be 
coated on the projections depending from the lid. Upon covering of the 
device with the lid these additional reagents come into contact with the 
sample in the wells. 
In accordance with the preferred embodiment of the present invention, the 
device is chemically isolated, and well-suited for use in clinical 
microbiology applications including, but not limited to, chemical, 
immunochemical and microorganism identification and antimicrobic 
sensitivity testing. 
The device is disposable, self-contained and is able to produce aliquots of 
substantially small volume in a rapid manner without a variety of sterile 
vessels, pipetting or sampling aids and multiple manipulations. 
The device solves the problem of filling an aliquot into a small volume 
comprising a small diameter and/or height, without the need for pipetting 
or sampling aids and multiple manipulations. 
An advantage of the device is that it is able to allow isolation of sample 
aliquots so they may be reacted or modified in an individually selective 
manner. The multiple aliquots may be treated with the same or different 
reagents or other chemical additives. 
A further advantage is that the device provides a convenient means for 
simultaneously and effectively inoculating a large number of individual 
wells of a small volume comprising a small diameter and/or height, without 
the need for multiple filling and distributing steps. 
Another advantage of the device is that air is easily expelled from each 
well so that the sample may easily fill into each well and also so that 
the aliquot remains in the well even upon manipulating or inverting the 
device. 
A further advantage of the device is that consistent results may be 
obtained when testing the sample because of the substantially equal, rapid 
and reproducible filling of each well, the substantially equal volume of 
all the aliquots and because air has been expelled from the wells during 
filling. 
The device also allows for easy visual or machine examination of individual 
sample aliquots and reduces the total amount of starting sample required 
for use by allowing aliquots of a small volume to be distributed. 
With the foregoing and additional features in view, this invention will now 
be described in more detail, and other benefits and advantages thereof 
will be apparent from the following description, the accompanying 
drawings, and the appended claims.

DETAILED DESCRIPTION 
While this invention is satisfied by embodiments in many different forms, 
there is shown in the drawings and will herein be described in detail 
preferred embodiments of the invention, with the understanding that the 
present disclosure is to be considered as exemplary of the principles of 
the invention and is not intended to limit the invention to the 
embodiments illustrated. Various other modifications will be apparent to 
and readily made by those skilled in the art without departing from the 
scope and spirit of the invention. The scope of the invention will be 
measured by the appended claims and their equivalents. 
Referring to the drawings, there is illustrated a device according to the 
present invention for receiving, distributing and storing multiple 
aliquots of a sample to be tested or analyzed. 
The preferred embodiment of device 10 comprises an outer-base element 11, a 
sample distribution element 30 and a lid 50 as shown in FIG. 1. 
Device 10 is typically, but not limited to, a rectangular shape with the 
wells in an ordered array of parallel rows. The outer-base element and the 
lid are preferably an optically clear plastic to facilitate viewing of the 
wells. The sample distribution element is preferably made of an opaque 
colored plastic, most preferably white plastic, to provide contrast and 
prevent interference of colored sample in the wells with one another. 
The outer-base element 11 as shown in FIGS. 2 and 2(a) comprises a bottom 
12, an inner planar surface 14, depending sidewalls 15, 16, 17 and 18, 
shelf like projections 20 and 21 located on the inner side of two opposite 
sidewalls, circular well bottoms 22 slightly raised from inner planar 
surface 14 and attachment posts 24 raised from the inner planar surface. 
Sidewalls 15, 16, 17 and 18 meet and are perpendicular with inner planar 
surface 14 
Sample distribution element 30 as shown in FIGS. 3, 3(a) and 3(b) comprises 
an upper surface 31, a lower surface 32, wells 34, a trough 35, a 
reservoir 36 and attachment bosses 38. The sample distribution element is 
preferably disposed within the outer-base element. 
Each well 34 in sample distribution element 30 is substantially disposed 
between upper surface 31 and lower surface 32 and transversely disposed 
with respect to trough 35. Each well comprises a circular sidewall 39, a 
sidewall bottom surface 37, an upper mouth opening 40 and a bottom mouth 
opening 41. Each well is substantially perpendicular to the trough to form 
a substantially sharp junction at the upper mouth opening. It is believed 
that the substantially sharp junction provides a means for effectively and 
efficiently separating individual aliquots from the sample. 
Each well size may be varied by changing well cross section or depth. The 
wells are shown in a circular configuration, but may have any cross 
sectional geometry. The wells preferably are in a three by ten matrix of 
thirty equal sizes as shown in FIG. 3(a). The bottom mouth opening of each 
well corresponds with a well bottom of the outer-base element as shown in 
FIG. 4. 
Attachment posts 24 of the outer-base element mate with corresponding 
attachment bosses 38 on the sample distribution element to secure the 
sample distribution element to the outer-base element as also shown in 
FIG. 4. 
Preferably the device is formed wherein sidewall bottom surface 37 and 
circular well bottom 22 are not sealed or fastened to each other. As shown 
in FIG. 4 the sidewall bottom surface and the well bottom are preferably 
substantially parallel to each other to form a variable space 26 between 
them for allowing only air to escape from the wells as sample enters. 
Projections 25 may be on the periphery surface of well bottoms 22 as shown 
in FIG. 4(a) or as projections 44 on the periphery surface of the sidewall 
bottom surface 37 as shown in FIG. 4(b) so as to vary the space between 
the sidewall bottom surface and the well bottom. Most preferably, on the 
periphery surface of the well bottom or the sidewall bottom surface is a 
textured or abraded surface formed by abrasion, texturing, sanding or the 
like. 
Sample distribution element preferably comprises a reservoir 36 for 
receiving, distributing and/or storing liquid sample and/or for holding 
excess sample, which is connected to trough 35. Sample is poured or 
pipetted into the reservoir and then enters the trough. Preferably, the 
trough is a unidirectional pathway substantially perpendicular to the 
mouth opening of all the wells, ending at the last well and beginning at 
the reservoir. 
Sample is distributed to each well by the trough by manually tilting the 
device slightly so that the sample in the reservoir flows in the trough. 
Once the sample has traveled to the last well, and if there is excess 
sample, the device is again tilted to make any undistributed sample pass 
back along the same path to the reservoir. The trough assures that a 
sample is allowed to pass over each well two times for complete filling. 
The sharp junction of the upper mouth opening and the trough provides a 
means for effectively and efficiently separating individual aliquots from 
the sample. 
The sample flows from the upper mouth opening of each well through to the 
variable space between the sidewall bottom surface of the well and the 
well bottom after air has been expelled. It is believed that the weight of 
the sample forces the air or air bubbles to be pushed through the variable 
space. It is further believed that the combination of frictional forces, 
hydrostatic pressure differential and the sample surface tension prevents 
the sample from flowing beyond the variable space between the sidewall 
bottom surface of the well and the well bottom. Furthermore, the sample 
remains in the well and in the variable space between the sidewall bottom 
surface of the well and the well bottom even when the device is 
manipulated or inverted. The removal and prevention of air in each well 
allows for accurate, consistent and efficient testing and analysis of each 
aliquot. 
The filling features of the present invention provide a means for 
distributing a small volume of an aliquot. The filling features are most 
useful when the upper mouth opening of each individual well is of a small 
diameter and/or the well circular sidewall is a small height. The small 
diameter of the upper mouth opening is allowed because of the function of 
the spaced means. 
The upper mouth opening of each well is preferably from about 0.01 inches 
(0.03 cm) in diameter to about 0.25 inches (0.64 cm) and most preferably 
at about 0.16 inches (0.41 cm) Each well circular sidewall is preferably 
less than about 2 inches (5 cm) in height, desirably from about 0.04 
inches (0.1 cm) to about 2 inches (5 cm) and most preferably at about 0.16 
inches (0.41 cm). 
The individual wells may also be coated with dried reagents that are 
reconstituted by the liquid sample or with immobilized reagents for solid 
phase tests. 
As shown in FIG. 5, removable lid 50 comprises an upper surface 51, a lower 
surface 52, a depending edge 60 and depending sidewalls 54, 55, 56 and 57. 
The removable lid also further comprises a plurality of projections 59 
raised from lower surface 52 with a tip 61 on the unconnected end of each 
projection. Sidewalls 54, 55, 56 and 57 meet and are substantially 
perpendicular with lower surface 52. Depending edge 60 is substantially 
perpendicular to the sidewalls and follows the perimeter of upper surface 
51. 
The lid removably covers the sample distribution element disposed within 
the outer-base element. Sidewalls 54, 55, 56 and 57 and depending edge 60 
serve to mate closely with outer-base element 11 forming a humidity 
control system for restricting evaporation of liquid from the device. Most 
preferably used to hold the lid and the outer-base element together are 
shelf like projections 20 and 21 on the outer-base element and depending 
edge 60 on the lid. 
As is shown in FIG. 5a, various labels and identifying marks are preferably 
applied or molded into the lid of the device. 
A most preferred embodiment of lid 50 is wherein a sponge or absorbent pad 
70 is on the lower surface of the lid to draw up any excess sample from 
reservoir 36 of the sample distribution element as illustrated in FIG. 5. 
Each projection on the lid is preferably arranged to align with each well. 
As shown in FIG. 4, each projection is slightly smaller in dimension than 
each well upper mouth opening and is preferably of a length such that it 
just touches the surface of the liquid aliquot in each well after filling. 
Tip 61 on each projection is preferably precoated with reagents for 
delivery to the aliquot in each well. 
Each projection, preferably has a one-to-one correspondence with each well, 
to provide a means for each well to be separately and individually reacted 
with chemical reagents or other materials for typical analytical purposes. 
The lid optionally has circular optical extensions 62 which are raised up 
from upper surface 51 of the lid and connected to a projection as shown in 
FIG. 5. Extensions 62 may be used to view an optical path for visual or 
machine examination of the sample through projections 59 and through the 
aliquot in the well to well bottom 22. 
The extensions and the projections serve to enhance the optical path of the 
device and eliminate problems from condensation common with simple lids 
due to their contact with the aliquot in each well. These components 
eliminate liquid to air and air to plastic interfaces in the viewing path 
of the well and the lid. 
The lid optionally has a sealable opening 65 for adding liquid reagents to 
the aliquots in the wells. As shown in FIG. 6, the sealable opening is on 
the upper surface of the lid and may be effectively covered by sealing 
tape 66 affixed to the lid over opening 65. The sealable opening is 
surrounded by a funnel area 67 for easy access of reagent to be added to 
the opening. The tape can be removed by use of a tape pull tab which is 
not sealed to the lid. Liquid sample is dispensed into the opening and 
flows through the funnel and then to a conduit 64 which is molded into the 
lower surface of the lid and connected to the opening. Each conduit is 
preferably rectangular in cross section and directs flow of the sample to 
projection 59. In this embodiment, the projection further comprises a 
concave surface 63 for receiving liquid reagents for delivery or drying. 
Sealable opening 65 and conduit 64 may be connected to more than one 
projection to add a single reagent to multiple sample aliquots in their 
individual wells. 
Additionally, lid 50 serves to protect the user from the contents of the 
device should it contain a harmful or potentially harmful material such as 
a microorganism suspension. In the preferred embodiment, sidewalls 54, 55, 
56 and 57 extend beyond projections 59 to form a barrier to the loss of 
fluid by evaporation when fitted into the device of the outer-base element 
and over the sample distribution element. The lid sidewalls further 
function to protect precoated projections from the outside environment 
prior to use. The sidewalls may also hold a removable seal element that 
protects the projections. 
The device may be used for the rapid separation of a sample into numerous 
aliquots and the treatment of any or all of the aliquots with the same or 
different reagents, substrates or other chemical additives. 
The device is suitable for identifying microbes such as E. coli and 
Klebsiella pneumoniae in sample aliquots. Substrates useful for the 
identification or differentiation of microbes may be added to each aliquot 
by manual pipetting or by using the lid projections of the device. 
Interaction of an organism and the substrate may be for example, detected 
by a chemical or optically detectable change such as color of the aliquot. 
Other identifying and differentiating methods may use the removable lid to 
deliver substrates to each aliquot to produce distinct reactions in each 
aliquot. 
The present invention may be embodied in other specific forms without 
departing from the spirit or essential attributes thereof. 
The example is not limited to any specific embodiment of the invention, but 
is only exemplary. 
EXAMPLE 1 
METHOD AND APATUS FOR PRODUCING MULTIPLE ALIQUOTS PIPETTE FILLING VS 
DIRECT FILLING 
Two devices A and B of the present invention molded of Polysar 555 
polystyrene were utilized to demonstrate the ability of the invention to 
produce essentially equal aliquots of a sample. The units were first 
analyzed by recording their optical density in a dry state using a 
spectrophotometer (Dynatech Model MR700, Dynatech Laboratories, McLean VA) 
to make readings at 560 nanometers. 
A solution of phenol red dye was prepared by dissolving 0.047 gm in 100 ml 
of a 0.067M phosphate buffer at pH 7.5. A pipette was utilized to dispense 
0.0060 ml of the dye solution onto the projections of lid A. Sample 
distribution element A was filled with the dye solution and then covered 
with lid A. 
Sample distribution element B was directly filled with a 10:1 dilution of 
the dye and covered with lid B which had no solution on the projections. 
Table 1 shows the measured mean and standard deviations from the mean 
measured for each device. 
TABLE 1 
______________________________________ 
Standard Coefficient 
Device 
Mean OD at 560 NM 
Deviation of Variation (%) 
______________________________________ 
A 1.357 0.053 3.9% 
B 1.171 0.015 1.3% 
______________________________________ 
The procedure of dispensing the dye by pipette yielded a slightly higher 
coefficient of variation than direct filling. This is, in part, due to the 
relative difficulty of pipetting such small volumes. The coefficient of 
variation of less than 2% for device B, and less than 4% for device A, are 
adequately reproducible for procedures in analytical microbiology. This 
example also demonstrates the use of the lid projections to receive a 
liquid reagent, have reagent dried for storage and then have said dried 
reagent be reproducibly delivered and rehydrated or dissolved in the equal 
volume aliquots produced by the invention. Time required to produce the 
sample aliquots using the device of the present invention was less than 30 
seconds.