# US 10,371,608 B2 · Sample preservation method and sample preservation substrate

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- Number: US 10,371,608 B2
- Document ID: US10371608B2
- Status: Granted
- Kind: B2
- Application number: 14/355,027
- Filed: 2012-10-29
- Published: 2014-10-09
- Granted: 2019-08-06
- Earliest claimed: 2011-10-31
- Assignees: GE Healthcare Bio-Sciences AB
- Applicants: Ge Healthcare Bio-Sciences AB
- Inventors: Mattias Algotsson; Miles W. Burrows; Jimmy Hedin Dahlstrom; Ylva Laurin; Ronnie Palmgren; Jinyu Zou
- Web page: https://patentgrep.com/patent/US10371608B2

## CPC

- G01N 1/28: Preparing specimens for investigation {including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q}(mounting specimens on microscopic slides G02B21/34; means for supporting the objects or the materials to be analysed in electron microscopes H01J37/20 {; laboratory gas handling apparatus B01L5/00})
- B01L 3/50: {Containers for the purpose of retaining a material to be analysed, e.g. test tubes (devices for taking samples of blood A61B5/15)}
- D21H 13/40: vitreous, e.g. mineral wool, glass fibres
- D21H 17/22: Proteins
- D21H 17/24: Polysaccharides
- D21H 17/52: Epoxy resins
- B01L 2300/126: Paper
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR

## Abstract

The invention discloses a cellulose or glass fiber paper for preservation of biological samples, which comprises 4-30 wt % of a hydrophilic branched carbohydrate polymer. It also discloses a method for preservation of biological samples by applying and drying them on the paper.

## Claims

### Claim 1

A method for preserving a biological sample, the method comprising:
a) providing a paper having a surface weight of 40-800 g/m2, the paper comprising cellulose fibers or glass fibers, and further comprising 4-30 percentage by weight (“wt %”) of a hydrophilic branched carbohydrate polymer in the paper wherein the carbohydrate polymer is covalently bound to the cellulose fibers or glass fibers, and wherein water extractables in the paper are 0.1-25 wt %;
b) applying the biological sample on the paper and forming a sample spot with the applied sample absorbed on the paper; and
c) drying the paper with the applied sample absorbed thereon, thereby preserving the biological sample.

### Claim 2 (depends on 1)

The method of claim 1, wherein the biological sample is a whole blood sample.

### Claim 3 (depends on 1)

The method of claim 1, further comprising storing the dried paper for at least one week.

### Claim 4 (depends on 1)

The method of claim 1, wherein the paper comprises 10-25 wt % of the carbohydrate polymer.

### Claim 5 (depends on 1)

The method of claim 1, wherein a residual moisture content of the dried sample paper is less than 10%.

### Claim 6 (depends on 1)

The method of claim 1, wherein water extractables in the paper are 0.1-5 wt %.

### Claim 7 (depends on 1)

The method of claim 1, wherein the water extractables in the paper are 3-20 wt %.

### Claim 8 (depends on 1)

The method of claim 1, wherein the carbohydrate polymer has an average molecular weight of about 70-400 kDa.

### Claim 9 (depends on 1)

The method of claim 1, wherein a 10 wt % water solution of the carbohydrate polymer has a viscosity of 1-10 mPas at 20° C.

### Claim 10 (depends on 1)

The method of claim 1, wherein the carbohydrate polymer is a polysucrose.

### Claim 11 (depends on 1)

The method of claim 1, further comprising storing the dried paper and extracting the biological sample from the dried paper after storage, the extracted biological sample further comprising a protein preserved in a biologically active state.

### Claim 12 (depends on 11)

The method of claim 11, wherein the protein is a storage-sensitive protein.

### Claim 13 (depends on 11)

The method of claim 11, further comprising recovering the protein in the biologically active state with a recovery of at least 60%.

### Claim 14 (depends on 1)

The method of claim 1, further comprising storing the dried paper at a storage temperature of at least 0° C.

### Claim 15 (depends on 14)

The method of claim 14, wherein the storage temperature is 0-40° C.

### Claim 16 (depends on 1)

The method of claim 1, wherein the paper further comprises 5-300 micromole/g negatively or positively charged groups, wherein the negatively or positively charged groups are covalently bound to at least one of the cellulose fibers, the glass fibers, or the carbohydrate polymer.

### Claim 17 (depends on 16)

The method of claim 16, wherein the negatively charged group is a carboxylate group.

### Claim 18 (depends on 16)

The method of claim 16, wherein the positively charged group is an amine group.

### Claim 19

A method for preserving a biological sample, the method comprising:
a) providing a paper comprising cellulose fibers or glass fibers, and further comprising 4-30 percentage by weight (“wt %”) of a hydrophilic branched carbohydrate polymer in the paper wherein the carbohydrate polymer is covalently bound to the cellulose fibers or glass fibers, the carbohydrate polymer is a polysucrose, and water extractables in the paper are 0.1-25 wt %;
b) applying the biological sample on the paper and forming a sample spot with the applied sample absorbed on the paper; and
c) drying the paper with the applied sample absorbed thereon, thereby preserving the biological sample.