BLOCKING METHOD

1 . A method of applying a blocking composition on a substrate for an assay, the method comprising:

providing a substrate for an assay, wherein the substrate for an assay comprises a solid substrate provided with a plurality of discrete spots of a biological material on a surface thereof; and

spraying the blocking composition onto the substrate as particles or droplets having a diameter being less than the diameter of the printed spots of biological material.

2 . A method according to claim 1 , wherein the method comprises spray coating the blocking composition onto the substrate.

3 . A method according to claim 1 , wherein the substrate is provided with an array of the biological material on a surface thereof.

4 . A method according to claim 1 , wherein the substrate for an assay comprises a microarray.

5 . A method according to claim 1 , wherein the size of the spots of biological material on the surface of the substrate is about 100 µm - 300 µm.

6 . A method according to claim 1 , wherein the blocking composition comprises, consists essentially of or consists of a blocking buffer.

7 . A method according to claim 1 , wherein the biological material comprises a peptide, a protein, an amino-acid, a nucleic acid, oligonucleotide, DNA, RNA, a lipid, a carbohydrate, an enzyme, a metabolite, an antibody, an antigen, a cell, red blood cells, plasma, or serum.

8 . A method according to claim 1 , comprising spraying the blocking composition onto the substrate using an air pressure-driven spray coating device.

9 . (canceled)

10 . A method according to claim 1 , comprising spraying the blocking composition onto the substrate using an ultrasonic atomiser.

11 . (canceled)

12 . A method of applying a blocking composition on a substrate for an assay, the method comprising:

providing a substrate for an assay, wherein the substrate for an assay comprises a solid substrate provided with a plurality of discrete spots of a biological material on a surface thereof, and wherein the surface of the substrate is substantially planar; and

spraying the blocking composition onto the substrate.

13 . A method according to claim 1 , comprising at least one of: preserving the integrity of a/the biological material immobilised thereto; and/or improving specificity and/or sensitivity during subsequent analysis.

14 . (canceled)

15 . A method according to claim 1 , wherein the method reduces, avoids and/or prevents the occurrence of aberrant results,

optionally wherein the method reduces, avoids and/or prevents the occurrence of false positive and/or false negative results.

16 . A method according to claim 1 , further comprising:

applying a sample on the blocked substrate, and

analysing the substrate.

17 . An apparatus for applying a blocking composition on a substrate for an assay, the apparatus comprising:

a substrate support for receiving the substrate for an assay; and

a spraying device configured to spray the blocking composition on the substrate, wherein the spraying device is configured to spray the blocking composition as particles or droplets having a diameter being less than the diameter of printed spots of biological material being provided on the substrate.

18 . An apparatus according to claim 17 , wherein the substrate is provided on a substrate holder, and wherein the substrate support has a receiving element configured to support the substrate holder.

19 . An apparatus according to claim 17 , wherein the substrate support comprises a masking element configured to be positioned over the substrate or substrate holder, wherein the masking element is configured to cover a peripheral region of the substrate which is devoid of any biological material on its surface, wherein the masking element has an opening near a central region thereof.

20 . (canceled)

21 . An apparatus according to claim 17 , wherein the apparatus comprises an enclosure configured to at least partially surround or contain the spray coating device, wherein the enclosure includes a support frame configured to connect and secure the spraying device, wherein the support frame is configured to connect and secure a first mounting plate, wherein the first mounting plate is configured to support a first spraying device.

22 - 23 . (canceled)

24 . An apparatus according to claim 17 , wherein the apparatus comprises a first connecting element configured to allow adjustment of the position of the spraying device or first spraying device.

25 . An apparatus according to claim 17 , wherein the spraying device or first spraying device comprises an ultrasonic atomiser.

26 . An apparatus according to claim 17 , wherein the apparatus comprises a movable platform configured to receive the substrate support, wherein the movable platform comprises one or more moving means to allow the movable platform to be moved in a first direction, and one or more moving means to allow the movable platform to be moved in a second direction transverse to the first direction.