Microcollection tube assembly

The present invention is a collection assembly useful for collecting small quantities of blood. The assembly comprises a container with an integral lip for facilitating collection of the blood and a cap suitable for enclosing the container. The assembly further comprises a sealing arrangement for securing the cap with the container and a cam arrangement for unsecuring the cap from the container.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a collection assembly and more particularly to a 
microcollection container and cap suitable for collecting small quantities 
of blood from a patient and maintaining the blood in secure fashion for 
subsequent testing. 
2. Description of Related Art 
Analytical instrumentation has made it possible to carry out a variety of 
hematological diagnostic procedures on very small quantities of blood. 
Because of this, a patient's finger or earlobe, for example, may be 
punctured and a very small quantity of blood may be rapidly collected into 
a container for such testing. However, in order to carry out testing and 
analysis on small quantities of blood, the blood must be rapidly collected 
prior to any coagulation thereof. 
A collection arrangement as described in U.S. Pat. No. 4,397,318, has been 
provided wherein a cap is configured to fit the top of a microcollection 
container with the cap having a removable capillary scoop for engaging the 
puncture site and transferring blood to the container. However, with such 
an arrangement, if precise positioning is not carried out, capillary 
action is not initiated or slowed and the collected blood will clot. 
Moreover, when a sample is taken with this collection arrangement, blood 
droplets may be left in and around the top area of the container. When the 
scoop is removed from the cap and the cap is fitted onto the top of the 
container, the excess blood may be forced onto the outside surface of the 
container. 
SUMMARY OF THE INVENTION 
The present invention is a collection assembly comprising a container and a 
cap. The cap preferably comprises a top portion, a bottom portion, and an 
annular skirt extending from the top portion to the bottom portion having 
an inner surface and an outer surface. The cap further includes an inner 
inverted skirt portion surrounded by the inner surface of the annular 
skirt. Most preferably the inner inverted skirt portion is separated from 
the inner surface of the annular skirt by an annular space. Most 
preferably, the cap also includes a cam follower positioned on the bottom 
portion. Desirably, the inside surface of the annular skirt comprises at 
least one protrusion and the inner inverted skirt portion has a sealing 
ring. The cap further comprises a rim extending from the outer surface of 
the annular skirt. 
The container preferably comprises an open top portion, a closed bottom 
portion, a sidewall extending from the top portion to the bottom portion 
and an open end associated with the top portion having an integral 
collector. Most preferably the integral collector is a scoop that is the 
same diameter as the inner diameter of the container so that no air vent 
is required. 
Preferably, the container further includes a cap seating flange associated 
with the outer diameter of the top portion of the container and an 
extending annular skirt associated with the bottom portion. Most 
preferably, a reservoir is positioned within the cap seating flange and at 
least one lug is located in the reservoir. Preferably, the container also 
includes a locking ring associated between the integral collector and the 
cap seating flange. 
Preferably, the collection assembly includes means for securing the inner 
surfaces of the cap to the top portion of the container by the interaction 
of the protrusions of the cap with the locking ring of the container and 
the sealing ring of the cap with the inside surface of the top portion of 
the container. Most preferably, the collection assembly also includes 
means for unsecuring the cap from the container by a cam arrangement on 
the cap and container. This cam arrangement assists in substantially 
reducing fluid splatter from the container when the cap is removed from 
the container. 
In a preferred embodiment of the invention, the cam arrangement includes at 
least one cam follower positioned on the bottom portion of the cap and at 
least one cam surface positioned in the cap seating flange of the 
container. A downwardly rotational force applied to the cap and an 
upwardly force applied to the container along the longitudinal axis, 
causes the cam follower and the cam surface to align and the cap to 
snap-seal to the container by the interaction of the protrusions of the 
cap with the locking ring of the container and the sealing ring of the cap 
with the inside surface of the top portion of the container. This action, 
which may cause an audible-snap, in turn seals the container by 
compressing the protrusions of the cap against the locking ring of the 
container and the sealing ring of the cap against the inside surface of 
the top portion of the container to form a non-permanent lock and to 
substantially prevent the outer surface of the top portion of the 
container from making contacting with the inside surface of the cap's 
annular skirt. 
The cap and container are then unsecured in a twist off manner by applying 
a rotational force to the cap. Most preferably, an upward rotational force 
is applied to the cap and a downwardly force applied to the container 
along the longitudinal axis. This causes the cam follower to rise on the 
cam surface and in turn the cap is unsecured from the container. An 
important advantage of the present invention is that the rotational force 
applied to the cap can be bi-directional, that is clockwise or 
counter-clockwise. 
The collection assembly of the present invention is preferably used in 
micro-centrifuges. However, an extension may be secured and unsecured to 
the bottom portion of the container. The extension increases the length 
dimension of the container. With the extension, the container may be 
compatible with standard clinical centrifuges. 
An advantage of the present invention is that any excess fluid on the 
outside surface of the integral collector is directed downwardly into the 
cap seating flange by the inner surface of the annular skirt of the cap 
when a downward force is applied to the cap as the cap and container are 
being secured. Therefore, radial spray of excess fluids are minimized. 
Another advantage of the invention is that the cap may be secured and 
unsecured to the bottom portion of the container. In particular, the 
annular space in the cap between the annular skirt and inverted skirt 
allows the cap to be removably secured with the bottom portion of the 
container by receiving the annular skirt of the container. 
Still another advantage of the invention is that the recessed inverted 
skirt and the sealing-ring substantially reduces cap contact with fluid 
collected in the container. Therefore the inner surfaces of the cap may be 
minimally exposed to fluid collected in the container when the cap is 
secured to the top portion of the container. 
Another advantage of the present invention is that the outer surface of the 
cap may preferably be configured to substantially limit movement or 
rolling of the cap or the assembly. This applies whether the cap is 
positioned with the top portion or bottom portion of the container. 
Still another advantage of the present invention is that when the cap is 
secured to the container, the rim of the cap substantially prevents 
contamination to the specimen inside the container.

DETAILED DESCRIPTION 
Referring to the drawings in which like reference characters refer to like 
parts throughout the several views thereof, FIG. 1 illustrates a 
collection assembly 10 comprising a container 12 and a cap 14. 
As illustrated in FIG. 1, container 12 has a sidewall 22 having an outer 
surface 24 and an inner surface 26. The sidewall extends from an upper 
portion 28 to a lower portion 30. Upper portion 28 includes an open end 31 
and an inner surface 27 with a top surface 32 having an integral lip 
portion 34 with a receiving edge 36. Lower portion 30 comprises a closed 
bottom end 38 and an annular skirt 37 extending from the closed bottom end 
and outer surface 24 to define a compartment area 39. Annular skirt 37 
provides a means for allowing the container to be placed upright on a flat 
surface. 
Upper portion 28 has a cap seating flange 40 positioned around the outer 
surface of the container which defines a well or trough 42 and an outer 
surface 41. The cap seating flange has an upper surface edge 43 and a 
plurality of lugs 44 each having a cam surface 46. Although a container 
having only one projecting lug is within the purview of the instant 
invention, a plurality of lugs is preferred. Also, although other shapes 
and configurations are within the purview of the instant invention, lugs 
44 of this embodiment are triangularly shaped. 
As shown in FIG. 2, further positioned on the outer surface of the 
container on the upper portion is a locking ring 48 positioned between 
receiving edge 36 of integral lip portion 34 and cap seating flange 40. 
The locking ring has an upper edge 50 and a lower edge 52. 
Cap 14 as shown in FIG. 3, has a top surface 54, a bottom stop ledge 56 and 
an annular outer skirt 58 extending from the top surface to the bottom 
stop ledge. The annular outer skirt has an outer wall surface 60 and an 
inner wall surface 62. A shield 66 extends from the outer wall surface of 
the annular outer skirt and has an outer surface or circumference 76. 
As shown in FIG. 3, cap 14 also has an inner annular inverted recessed 
skirt portion 64 that extends from top portion 54 to a bottom surface 63. 
The inverted recessed skirt portion defines a compartment or cup area 65 
on the top portion of the cap. The inner wall surface of the annular outer 
skirt and the inner annular inverted recessed skirt are spaced from each 
other to define an annular space 68. The cap further includes, a plurality 
of circumferentially spaced protrusions 70 positioned on inner wall 
surface 62 and a sealing ring 67 positioned on inverted recessed skirt 
portion 64. Projecting lugs 72 are located on bottom stop ledge 56 wherein 
each lug comprises a cam follower surface 74. Although a cap having only 
one projecting lug is within the purview of the instant invention, a 
plurality of lugs is preferred. Also, although other shapes and 
configurations are within the purview of the instant invention, lugs 72 of 
this embodiment are triangularly shaped. 
As shown in FIG. 4, flats 77 are positioned on the outer surface of shield 
66. The flats substantially prevent the cap from rolling and provide a 
convenient grasping surface for ready removal and placement of the cap on 
the container. Although a shield with a smooth outer circumference without 
flats is within the purview of the instant invention, a shield with an 
outer surface with flats is preferred. 
As shown in FIG. 5, when cap 14 is removably secured to container 12, space 
68 of the cap receives the top portion of the container including the 
integral lip, protrusions 70 bear against lower edge 52 of locking ring 48 
of the container, sealing ring 67 bears against inner surface 27 of the 
container and cam follower 74 contacts cam surface 46. Shield 66 covers 
outer surface 44 of cap seating flange 40 mid bottom stop ledge 56 abuts 
with upper surface edge 43 of the cap seating flange 40, so as to form a 
non-permanent lock and substantially prevent any excess fluid in well 42 
of the cap seating flange from spilling out. Any fluid that migrates 
between upper surface edge 43 and bottom stop ledge 56 is directed in a 
downward direction along the container. Further, any fluid in well 42 is 
substantially contained by the upper surface edge of the cap seating 
flange and the bottom stop ledge of the cap. 
Cam follower surface 74 and cam surface 46 are configured so that a 
downwardly rotational force applied to cap 14 about longitudinal axis 80 
causes cam follower 74 to contact cam surface 46. Cap 14 is snapped onto 
the top portion of the container as guided by cam follower surface 74 and 
cam, surface 46. Cap 14 is removably secured to container 12 by 
protrusions 70 and sealing ring 67 as they bear respectfully against lower 
edge 52 of the locking ring and inner surface 27 of the container. The 
position of the protrusions and sealing ring of the cap with the container 
forms space 69 between the outer surface of the top portion of the 
container and the inner wall surface of the cap's annular outer skirt. 
Therefore, wiping down of any fluid on the container's outer surface is 
substantially prevented. 
The cap is unsecured from the container in a twist-off manner by applying a 
rotational force about longitudinal axis 80 while holding the container. 
Rotation of the cap with respect to the container causes cam follower 
surface 74 to rise on cam surface 46 and in turn the cap is unsecured from 
the container. The rotational force applied to the cap can be 
bi-directional, that is clockwise or counter-clockwise. 
As shown in FIG. 6, cap 14 is readily compatible with skirt 37 on the lower 
portion of the container. Space 68 of the cap receives the skirt of the 
container. When the cap is positioned on the bottom of the container 
during fluid collection, the cap provides a means for allowing the 
container to be placed upright on a flat surface. 
As shown in FIGS. 7 and 8, extension 90 is optionally available to be 
inserted into skirt 37 on the lower portion of container 12. The extension 
may be optionally used to make the collection assembly compatible with 
standard centrifuges or the need for additional space for labeling. 
Multiple extensions may be used if needed. 
The collection assembly of the invention may be made of a clear molded 
thermoplastic material so that the specimen collected may be readily 
viewed. Representative materials include, for example, polyethylene, 
polypropylene and polyvinyl chloride. The collection container may 
incorporate a hydrophilic material or a silicon may be applied to the 
internal surface thereof for enhancing the flow of blood introduced into 
the container. 
Although is within the purview of the invention to provide caps which are 
colored to define specific forms of fluid collection containers containing 
materials for one reason or another or for defining the kind of 
examination to be conducted on the specimen collected, transparent caps 
may be provided. Also, it should be noted that the dimensions of the 
container are such as to provide space for labeling which may be important 
for identifying the collected specimens.