The present invention relates generally to dried biological fluid spot testing. More particularly, the present invention relates to devices and methods for holding dried biological fluid spotting membranes.
Dried biological fluid spot testing such as dried blood spot (DBS) testing is becoming increasingly popular for pharmaceutical companies in clinical trials. Collection sites for clinical trials may sample blood spots (or other types of biological fluid spots) in the field, allow the spots to dry, and then ship the spots at a lower cost than liquid samples due to the non-biohazard status of dried blood spots and the less rigorous requirements for temperature control. Blood spotting is also becoming useful in preclinical work as analytical chemists are required to store samples for Incurred Sample Reanalysis (ISR) studies, and dried blood spots have proven to be an effective way to stabilize the analytes and the matrix. Typically, DBS samples are prepared by applying drops of blood drawn from a finger or toe to an absorbent membrane or substrate (e.g., filter paper) of an appropriate composition. The blood saturates the membrane and is air dried for a period of time (e.g., several hours) sufficient to form an array of circular dried blood spots on the membrane. The spot-containing membrane (which, as described below, is typically housed in a cardboard holder) may then be stored in a plastic container and transported as needed without needing to be frozen. The dried blood spots may thereafter be separated from the bulk membrane by punching the dried blood spots to create individual dried blood spot disks. Analytes such as pharmaceutical compounds may then be extracted from the dried blood spots by any number of techniques and subjected to analytical testing. Other types of biological fluid samples may be dried and subsequently processed in an analogous manner.
Typically, the absorbent membrane is housed in a membrane holder that is made of cardboard or chipboard. The absorbent membrane is sandwiched between a top cardboard face and a bottom cardboard face. The top face is secured to the bottom face by adhesive. A user may access the absorbent membrane via a window that passes through the top face and/or the bottom face. Conventional cardboard holders have many problems. For instance, cardboard can bend or warp easily (during testing, handling, shipping, etc.) which can impede the uniformity of the absorbent membrane. As another example, chemicals in the adhesives used to secure the top cardboard face to the bottom cardboard face may contaminate blood samples on the absorbent membrane. Also, conventional cardboard holders are generally not reusable.
In view of the foregoing, there is a need for providing devices and methods specifically designed for effectively holding dried biological fluid spotting membranes. In particular, there is a need for providing a holding device for a dried biological fluid spotting membrane that is durable and effective in holding its form or shape (and thus the form or shape of the membrane) during testing (including automated testing), handling, shipping, etc. In addition, there is a need for providing a holding device for a dried biological fluid spotting membrane that minimizes (or eliminates) the use of chemical adhesives. There is also a need for providing a holding device for a dried biological fluid spotting membrane that is capable of being reused.
To address the foregoing problems, in whole or in part, and/or other problems that may have been observed by persons skilled in the art, the present disclosure provides methods, processes, systems, apparatus, instruments, and/or devices, as described by way of example in implementations set forth below.
According to one implementation, a holding device for a dried biological fluid spotting membrane includes a plastic top face, a plastic bottom face, and a pocket disposed between the top face and the bottom face. The plastic top face includes a window formed therein, and the window has a length and a height. The pocket has a length and a height, and is configured for receiving a dried biological fluid spotting membrane that is accessible through the window by a user during dried biological fluid spot testing.
In some implementations, the length of the window is less than the length of the pocket, and the height of the window is less than the height of the pocket.
In some implementations, the window of the top face is a first window and the bottom face comprises a second window formed therein. The second window has a length that is substantially the same as the length of the first window, and a height that is substantially the same as the height of the first window.
In some implementations, the holding device includes a plastic laminate layer and a plastic body. The plastic laminate layer includes the top face. The plastic body includes the bottom face and an opposing inner face. The laminate layer is adhered to the inner face.
In some implementations, the holding device includes a plastic top piece and a plastic bottom piece. The plastic top piece includes the top face and a first inner face opposing the top face. The first inner face includes a plurality of male components extending from the first inner face. The plastic bottom piece includes the bottom face and a second inner face opposing the bottom face. The second inner face includes a plurality of female components extending into the second inner face. The female components are configured for detachably mating with the male components.
According to another implementation, a method is provided for assembling a holding device. A dried biological fluid spotting membrane is positioned within a pocket of a plastic membrane housing. The membrane is secured within the pocket, and is accessible by a user via a window formed in a top face of the plastic membrane housing.
In some implementations, securing the membrane within the pocket includes overmolding a top piece onto an inner face of the plastic membrane housing. The inner face includes the pocket formed therein, and the top piece includes the top face.
In some implementations, securing the membrane within the pocket includes adhering a plastic laminate layer to an inner face of the plastic membrane housing. The plastic laminate layer includes the top face.
In some implementations, securing the membrane within the pocket includes detachably mating male components extending from a first inner face of a top piece with female components extending into a second inner face of a bottom piece of the membrane housing. The top piece includes the top face and the first inner face opposing the top face. The bottom piece includes a bottom face and the second inner face opposing the bottom face. The second inner face includes the pocket formed therein.
According to another implementation, a method is provided for using a holding device in which a membrane is secured in a pocket of the holding device. A dried biological fluid spot is formed on the membrane by accessing the membrane via a window of the holding device, applying a drop of a biological fluid sample to the membrane to form a biological fluid spot, and allowing the biological fluid spot to dry.
In some implementations, the method includes accessing the dried biological fluid spot via the window and extracting a portion of the dried biological fluid spot formed on the membrane.
In some implementations, the method includes removing the top piece from the bottom piece by detaching male components from female components. The membrane may be removed from the pocket. The removed membrane may be replaced with a second dried biological fluid spotting membrane by positioning the second membrane within the pocket. The second membrane may be secured within the pocket by detachably mating the male components and the female components.
Other devices, apparatus, systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
The invention can be better understood by referring to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.
In the context of the present disclosure, the term “fluid” refers generally to liquid-phase materials and gas-phase materials, unless a liquid-phase material or a gas-phase material is specifically indicated. The terms “liquid-phase” and “liquid,” and “gas-phase” and “gas,” are used interchangeably. A liquid-phase material or liquid may be any liquid, such as a solution, suspension, slurry, multi-phase mixture or the like, and may include gaseous components (e.g., bubbles) and/or solid components (e.g., particles). A gas-phase material or gas may be any gas or vapor, and may include liquid components (e.g., droplets) and/or solid components (e.g., particles). A “dried fluid sample” or a “dried fluid spot” refers generally to a material that was initially provided in the liquid phase and was thereafter dried, such as by air drying.
In the context of the present disclosure, the term “analyte” refers generally to any sample molecule of interest—that is, a molecule on which an analysis is desired such as, for example, a chromatographic analysis.
Examples of implementations of the subject matter disclosed herein will now be described in more detail with reference to
As illustrated in
The first window 112 has a length and a height. To more easily describe dimensions of various components of the present invention, lengths and heights of the various components will be described in relation to horizontal and vertical axes. Although the cross-sections of the holding devices 100 (and holding devices 400 and 500 discussed below in conjunction with
Returning to
As shown in
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The user of the holding device 100 may easily attach the top piece 104 to the bottom piece 106 by pressing the male components 226a-226d into the corresponding female components 126a-126b. The user of the holding device 100 may easily detach the top piece 104 from the bottom piece 106 by removing the male components 226a-226d from the female components 126a-126b (e.g., pulling the top piece 104 away from the bottom piece 106). The membrane 102 may be positioned in the pocket 108, and the top piece 104 may then be secured to the bottom piece 106. One or more dried biological fluid spots may be formed on the membrane 102. For example, a user (or an automated testing apparatus) may access the membrane 102 via the first window 112 (or, in some implementations, via the second window 312), and apply a drop(s) of a biological fluid sample to the membrane to form a biological fluid spot. The biological fluid spot may be allowed to dry over a period of time. A user may form a dried biological fluid spot on the membrane 102 without actually handling the membrane 102, which may decrease the likelihood of contamination of the biological fluid sample A user may extract a portion of the dried biological fluid spot (for example, by using a punch device, or any other suitable extraction apparatus) for assaying. A portion of the dried biological fluid spot may be extracted (e.g., punched) via the first window 112, for example. The membrane 102 does not have to be handled by a user in order to extract a portion of the dried biological fluid spot. The user may detach the top piece 104 from the bottom piece 106, and remove the membrane 102 from the pocket 108. In some implementations, the top piece 104 and bottom piece 106 may be sterilized after the membrane 102 is removed. The user may position a second membrane within the pocket 108. The user may secure the second membrane within the pocket 108 by detachably mating the male components 226a-226d and the corresponding female components 126a-126d. As may be seen from the present disclosure, the holding device 100 may be reused. The holding device 100 does not require the use of adhesives. Since the holding device 100 is made of injection molded plastic, the holding device 100 is a durable alternative to conventional cardboard holders. For example, the plastic holding device 100 may be less likely to bend or deform during shipping, handling, automated testing, etc.
The holding device 500 may be made according to the steps presented below. Unless expressly provided, the following steps are presented in no particular order. A bottom piece (not shown) may be injection molded. The membrane 102 may be positioned within the pocket 504. The top face 502 may be injection molded (or otherwise formed by a suitable fabrication technique) to the bottom piece (e.g., via overmolding, a process known by those skilled in the art).
It will be understood that various methods are intended to be within the scope of the present disclosure, including, but not limited to: methods for holding the dried biological fluid spotting membrane 102 during dried biological fluid spot testing; methods for assembling and disassembling the holding device 100, 400 or 500; methods for preparing the dried biological fluid spotting membrane 102 for dried biological fluid spot testing; and methods for using the holding device 100, 400 or 500 in the context of dried biological fluid spot testing. In conjunction with holding and/or using the holding device 100, 400 or 500, a window of the holding device 100, 400 or 500 may be utilized to access the membrane 102 for various purposes. For example, one or more drops of a biological fluid sample may be applied to the membrane 102 and allowed to dry (e.g., air dry) to create one or more dried biological fluid spots. As another example, a dried biological fluid spot or a portion thereof may be extracted from the membrane 102 via the window by any suitable means.
As one non-limiting example of extracting a dried biological fluid spot or portion thereof from the membrane 102, a punch device (or punch tool) may be operated to punch out a dried biological fluid sample unit (i.e., a portion of the membrane 102 containing the dried biological fluid spot or a portion of the dried biological fluid spot) from the membrane 102. For this purpose, the holding device 100, 400 or 500 may be placed or mounted on a suitable support surface, and the punch device may then be thrust through the window and through the membrane 102 where the target dried biological fluid spot is located. The punch device is typically cylindrical and thus the as-formed sample unit is typically disk-shaped. Once the sample unit has been formed it may be transported to an analytical device or any other desired destination. Depending on the design of the punch device, the as-formed sample unit may be captured in the punch device and transported therewith and/or the punch device may be utilized to perform certain sample preparation procedures such as, for example, solid phase extraction, sample clean-up, etc.
In some implementations, after forming the spot-containing sample unit, the sample unit may be exposed to a flow of one or more elution solvents (e.g., methanol, acetonitrile, ethanol, ethyl acetate, methyl tert-butyl ether, dichloromethane, chloroform, water, etc., with or without buffers or other additives) to create an analyte-inclusive liquid sample matrix. The analyte-inclusive liquid sample matrix may then be processed in any desired manner for separating, concentrating, purifying, and/or analyzing the analytes (i.e., subsequent analytical techniques) eluted from the sample unit. Examples of subsequent analytical techniques include, but are not limited to, protein precipitation, fraction collection, centrifugation, spectrophotometry, nuclear magnetic resonance (NMR) spectrometry, various types of SPE (e.g., normal-phase, reversed-phase, ion-exchange, etc.), and various types of chromatography (e.g., preparative chromatography, liquid chromatography (LC), gas chromatography (GC), etc.) as well as hyphenated techniques entailing mass spectrometry (LC/MSn, GC/MSn, etc.). Other subsequent analytical techniques include the testing or processing of genetic material (i.e., “genetic testing”) such as ribonucleic acid (RNA) or deoxyribonucleic acid (DNA). Examples of genetic testing include, but are not limited to, polymerase chain reaction (PCR), reverse transcriptase PCR (RT-PCR), ligase chain reaction (LCR), hybridization, genomic sequencing, labeling, assaying, etc. Hence, for example, in the case of sample units formed from dried blood spots, the eluents from these sample units may be tested for pharmaceutical compounds, other drug-related compounds, or other chemistries, or high molecular weight (HMW) molecules such as DNA, RNA, proteins or other polymers.
Some examples of punch devices and related devices that may be utilized in conjunction with the holding device 100, 400 or 500 include those disclosed in U.S. patent application Ser. No. 12/916,834, titled DRIED BIOLOGICAL FLUID SPOT PUNCH DEVICE AND RELATED METHODS, filed Nov. 1, 2010; and U.S. patent application Ser. No. 12/917,138, titled APPARATUS FOR PUNCHING AND SOLID PHASE EXTRACTION OF DRIED BIOLOGICAL FLUID SPOT AND RELATED METHODS, filed Nov. 1, 2010, both of which are incorporated herein by reference in their entireties.
As may be seen from the present disclosure, the holding devices 100, 400 and 500 described herein provide effective means for holding the membrane 102 during dried biological fluid spot testing, such as dried blood spot testing, including automated dried blood spot testing. In addition, the holding devices 100, 400 and 500 described herein provide effective means for holding the membrane 102 during shipping and handling. The holding devices 100, 400 and 500 may be held or manipulated in a manner that avoids having to contact the membrane 102 and the dried biological fluid spots contained thereon, thereby avoiding contamination of the dried biological fluid spots. In addition, the holding devices 100, 400 and 500 are effective in maintaining the form and/or shape of the membrane 102 during testing, thus facilitating reliable test results.
In general, terms such as “communicate” and “in communication with” (for example, a first component “communicates with” or “is in communication with” a second component) are used herein to indicate a structural, functional, mechanical, electrical, signal, optical, magnetic, electromagnetic, ionic or fluidic relationship between two or more components or elements. As such, the fact that one component is said to communicate with a second component is not intended to exclude the possibility that additional components may be present between, and/or operatively associated or engaged with, the first and second components.
It will be understood that various aspects or details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation—the invention being defined by the claims.