Patent Application
20230330678
Bio-layer interferometry (BLI) is an analytical technique commonly used to measure biomolecular interactions. BLI analysis commonly uses a multi-well sample tray with each well containing a biomolecule in a suitable liquid. A typical multi-well sample tray 2 has a plurality of regularly spaced sample wells 4 arranged in a rectangular configuration. In most configurations, sample tray 2 rests on a shaker or other device which provides movement sufficient to maintain the material 6 within sample wells 4 in the form of a suspension. Due to the continuous movement of sample tray 2 and the small sample size, evaporative loss of liquid material 6 from sample wells 4 sometimes occurs leading to a decrease in accuracy of the BLI analysis. See for example
In one embodiment the present invention provides an evaporation control cover for use with a multi-well sample tray. The multi-well sample tray has a plurality of regularly spaced sample wells as defined by an outer perimeter of sample wells, with additional sample wells located within the outer perimeter of sample wells. The evaporation control cover comprises a plurality of sample holes arranged to correspond to the plurality of sample wells. The sample holes are defined by an outer perimeter of holes with additional sample holes located within the outer perimeter of holes. Optionally, a fluid port located in the cover provides fluid communication through the cover. The sample holes located within the outer perimeter of holes have a first diameter while the sample holes forming the perimeter holes have a second diameter which is less than or equal to the first diameter. The evaporation control cover carries a downwardly projecting flange configured to fit over the multi-well tray.
In an alternative embodiment, the present invention provides an evaporation control cover for use with a multi-well sample tray. The multi-well sample tray has a plurality of regularly spaced sample wells defined by an outer perimeter of sample wells with additional sample wells located within said outer perimeter of sample wells. The evaporation control cover comprises a top. The top includes a plurality of sample holes corresponding to the plurality of sample wells. Additionally, the top carries a downwardly projecting flange configured to fit over the multi-well tray. The cover also includes a bottom. The bottom has a plurality of upwardly projecting ports providing fluid communication through the bottom. The upwardly projecting ports configured to correspond to said plurality of sample wells. The bottom carries an upwardly projecting flange configured to fit within the downwardly projecting flange of the top. The upwardly projecting flange and the upwardly projecting ports define a reservoir suitable for retaining a liquid. Further, the upwardly projecting ports provide fluid communication between the sample holes and the sample wells. This embodiment may optionally include a wettable insert capable of absorbing and releasing a liquid. The wettable insert has a plurality of insert holes corresponding to said plurality of sample wells.
In another alternative embodiment, the present invention provides an evaporation control cover for use with a multi-well sample tray. The multi-well sample tray has a plurality of regularly spaced sample wells arranged in a rectangular configuration as defined by a first outer perimeter row, a second outer perimeter row, a third outer perimeter row and a fourth outer perimeter row. The outer perimeter rows defining the rectangular configuration have a first corner well, a second corner well, a third corner well and a fourth corner well with additional rows of sample wells located within the rectangular configuration. The evaporation control cover comprises a top. The top includes a plurality of sample holes arranged in a rectangular configuration corresponding to the plurality of sample wells and defined by a first top outer perimeter row, a second top outer perimeter row, a third top outer perimeter row and a fourth top outer perimeter row. The top outer perimeter rows defining the rectangular configuration further include a first top corner hole, a second top corner hole, a third top corner hole and a fourth top corner hole with additional rows of sample holes located within the rectangular configuration. The sample holes located to the interior of the first top outer perimeter row, the second top outer perimeter row, the third top outer perimeter row and the fourth top outer perimeter row have a first diameter. The sample holes within the first top outer perimeter row, the second top outer perimeter row, the third top outer perimeter row and the fourth top outer perimeter row have a second diameter which is less than or equal to the first diameter. Additionally, the top carries a downwardly projecting flange configured to fit over the multi-well tray. The cover also includes a bottom. The bottom has a plurality of upwardly projecting ports providing fluid communication through the bottom. The upwardly projecting ports have a rectangular configuration corresponding to the plurality of sample wells. The rectangular configuration is defined by a first bottom outer perimeter row, a second bottom outer perimeter row, a third bottom outer perimeter row and a fourth bottom outer perimeter row. The bottom outer perimeter rows defining the rectangular configuration have a first corner upwardly projecting port, a second corner upwardly projecting port, a third corner upwardly projecting port and a fourth corner upwardly projecting port. Additional rows of upwardly projecting ports are located within the rectangular configuration. The bottom carries an upwardly projecting flange configured to fit within the downwardly projecting flange of the top. The upwardly projecting flange and the upwardly projecting ports define a reservoir suitable for retaining a liquid. Further, the upwardly projecting ports provide fluid communication between the sample holes and the sample wells. This embodiment may optionally include a wettable insert capable of absorbing and releasing a liquid. The wettable insert has a plurality of insert holes in a rectangular configuration corresponding to said plurality of sample wells.
The drawings included with this application illustrate certain aspects of the embodiments described herein. However, the drawings should not be viewed as exclusive embodiments. For simplicity and clarity of illustration, where appropriate, reference numerals may be repeated among the different figures to indicate corresponding or analogous elements and the drawings are not necessarily to scale. Throughout this disclosure, the terms “about”, “approximate”, and variations thereof, are used to indicate that a value includes the inherent variation or error for the device, system, the method being employed to determine the value, or the variation that exists among the study subjects. Finally, the description is not to be considered as limiting the scope of the embodiments described herein.
As depicted in
Alternatively, evaporation control cover 10 may be configured to permit movement of sample tray 2 while evaporation control cover 10 remains stationary. As depicted in
One embodiment of evaporation control cover 10 will be described with reference to
Without wishing to be bound by theory, the addition of liquids to wettable insert 30 is believed to enhance the functionality of evaporative control cover 10. Wettable insert 30 may have a thickness greater than Distance A depicted in
As depicted in
The wettable insert 30 may be pre-wetted through a variety of techniques, such as by applying a seal (e.g., film) over the top 20 and/or bottom 40 of the cover 10 to contain the wettable insert 30; sealing the cover 10 with the wettable insert 30 in a bag; and/or positioning one or more plugs around the holes 32 of the wettable insert 30. The plugs may be made from a variety of materials, such as elastomer or plastic. Other techniques may also be used in other embodiments for pre-wetting the wettable insert 30 with the desired fluid.
In an alternative embodiment, wettable layer 30 may be replaced with any suitable solution used to wet wettable layer 30. Similarly, placing a saturated salt or other compatible solution in reservoir 48 will likely create a high humidity environment over the sample wells 4 sufficient to provide the desired reduction in evaporative loss from wells 4. For example, a potassium sulfate saturated water solution is known to create a 98% humidity above the solution.
Top 20 includes a downwardly projecting flange 27. In the embodiment of
Top 20 includes a plurality of holes 22 providing fluid communication through top 20. As depicted in
Through multiple observations, sample wells 4 in the perimeter of multi-well sample tray 2 were determined to experience a higher rate of evaporative fluid loss than sample wells 4 to the interior of multi-well sample tray 2. Therefore, to provide the desired evaporative control, holes 22 in top 20 have differing diameters based on their location. Holes 22 located to the interior of perimeter rows 52-58 have a first diameter (D1). Holes 22 within perimeter rows 52-58 have a second diameter (D2) which is less than the first diameter and corner holes 62, 64, 66 and 68 have a third diameter (D3). The third diameter is equal to or less than the second diameter. Thus, the diameters for each location can be stated as D1≥D2≥D3. The sizes of the first diameter, second diameter and third diameter will depend on the configuration of evaporation control cover 10.
When evaporation control cover 10 has a configuration similar to that of
When evaporation control cover 10 has a configuration similar to that of
In some embodiments, the desired reduction in evaporation from sample wells 4 will be achieved when D2 is 50% of D1 and D3 is 33% of D1.
As depicted in
Bottom 40 carries an upwardly projecting flange 44. The region between upwardly projecting flange 44 and upwardly projecting ports 42 defines a reservoir 48. Reservoir 48 receives the wetting fluid through port 24 or alternatively through another opening 26 which permits fluid to pass between top 20 and bottom 40 into reservoir 48. Thus, liquid retained in reservoir 48 helps maintain wettable insert 30 sufficiently saturated to provide the desired evaporative control. Alternatively, as discussed above, reservoir 48 may be used to contain the desired liquid without the presence of wettable insert 30.
In some embodiments, upwardly projecting ports 42 in bottom 40 may have differing inside diameters based on their location. Upwardly projecting ports 42 located to the interior of perimeter rows 72-78 have a fourth inside diameter (D4). Upwardly projecting ports 42 within perimeter rows 72-78 have a fifth inside diameter (D5) which is less than or equal to the fourth diameter and corner holes 82, 84, 86 and 88 have a sixth inside diameter (D6). The sixth inside diameter is equal to or less than the fifth inside diameter. Thus, the diameters for each location can be stated as D4≥D5≥D6. The sizes of the fourth inside diameter, fifth inside diameter and sixth inside diameter will depend on the configuration of evaporation control cover 10. Upwardly projecting ports 42 also have outside diameters which may be from about 1 mm to about 3 mm greater than the corresponding inside diameters. When bottom 40 has ports 42 of differing sizes as outline above, top 20 may have holes 22 of uniform diameter. Likewise, when top 20 has holes 22 of differing sizes as previously defined, then bottom 40 may have projecting ports 42 of uniform diameter.
In most instances, D1 will equal D4, D2 will equal D5 and D3 will equal D6. Thus, when evaporation control cover 10 has a configuration similar to that of
When evaporation control cover 10 has a configuration similar to that of
In some embodiments, the desired reduction in evaporation from sample wells 4 will be achieved when D5 is 50% of D4 and D6 is 33% of D4.
While the embodiments of evaporation control cover 10 described above provide enhanced fluid retention and consistency across each well 4, an alternative embodiment in which each hole 22 has identical diameters and each projecting port 42 has identical diameters will also provide enhanced fluid retention. See Table 2 below.
To provide for passage of sensor probe 12 through evaporation control cover 10, wettable insert 30 has a plurality of holes 32. Thus, holes 32 are also arranged in the same manner as holes 22 and upwardly projecting ports 42 such that upwardly projecting ports 42 pass through holes 32. Thus, the diameters of holes 32 correspond to the outside diameters of the corresponding upwardly projecting ports 42.
Tests were conducted to demonstrate the effectiveness of evaporation control cover 10. Each test was conducted over a 16-hour period at 25° C. using a shaker operating at 1000 RPM. For the tests conducted using evaporation control cover 10, wettable insert 30 is a polypropylene material with a thickness of 1.6 mm. The wetting liquid was deionized water.
Table 1 serves as a control and reflects the fluid loss from wells 4 in the absence of evaporation control cover 10. As reflected by Table 1, on average each well retained only 41.5% of the original fluid volume. The standard deviation for Table 1 is 3.2% and the coefficient of variation (%CV) is 7.6%. Table 2 reflects the improvement provided by use of evaporation control cover 10 with all holes 22 having a diameter of 3.4 mm. As reflected by Table 2, on average each well retained 93.2% of the original fluid volume. The standard deviation for Table 1 is 3.1% and the coefficient of variation (% CV) is 3.4%. Table 3 reflects the further improvement provided by using evaporation control cover 10 with varying diameter holes 22 as described above. In this instance, outer perimeter holes 22 (52, 54, 56, 58) have diameters of 2.4 mm, while holes 22 to the interior have diameters of 3.4 mm and holes 22 at locations 62, 64, 66, 68 have diameters of 2 mm. As reflected by Table 3, on average each well retained 93% of the original fluid volume. The standard deviation for Table 1 is 1.8% and the coefficient of variation (% CV) is 2.0%. For the sake of clarity and with reference to
Thus, use of evaporation control cover 10 more than doubled the amount of fluid retained in each well 4. While the fluid retention provided by evaporation control cover 10 with identical holes 22 and with holes 22 of differing diameters is essentially identical, the version with holes 22 of differing diameters provides the further improvement of enhanced consistency from one well 4 to another well 4. Clearly, evaporation control cover 10 will provide a significant improvement to the evaluation of analytes as the improved fluid retention will improve confidence in the analytic results.
In still another embodiment, evaporation control cover 10 has a configuration similar to that of
Other embodiments of the present invention will be apparent to one skilled in the art. As such, the foregoing description merely enables and describes the general uses and methods of the present invention. Accordingly, the following claims define the true scope of the present invention.
