A sample holder, comprising: a sample holder assembly fixture adapted to receive a sample substrate having a sample thereon in mounting engagement and a slide holder, the slide holder comprising: a sample chamber (33, 33', 33") including a gasket, said sample chamber (33, 33', 33") adapted to be mounted on said sample holder assembly fixture; a fluid reservoir (31, 31', 203) in communication with said sample chamber (33, 33', 33"); a first port (37, 37', 37", 38, 38', 38") in fluid communication with said sample chamber (33, 33', 33") via a fluid channel (36, 36', 36"); a second port (41, 41', 41"), separate from said first port (37, 37', 37", 38, 38', 38"), in fluid communication with said sample chamber (33, 33', 33"); and wherein slide holder includes a plurality of spaced clips each of which is adapted to be received and engaged in a respective cut out of the sample holder assembly fixture, and said spaced clips being configured to receive said sample substrate, wherein when said sample substrate is engaged in said sample holder, sample supported by said sample substrate is in said sample chamber (33, 33', 33"); characterized in that said fluid channel (36, 36', 36") is delimited by a region of the gasket (35, 35', 35", 401) included in said sample chamber (33, 33', 33") and in that said fluid channel (36, 36', 36") opens into said sample chamber (33, 33', 33") at an outlet opening (40, 40', 40"), wherein said fluid channel (36, 36', 36") and said outlet opening (40, 40', 40") are arranged such that, when fluid travels down said fluid channel (36, 36', 36") and out of said outlet opening (40, 40', 40") into said sample chamber (33, 33', 33"), the fluid fills said sample chamber (33, 33', 33") from the bottom up, thus reducing potential bubbles. a sample holder assembly fixture adapted to receive a sample substrate having a sample thereon in mounting engagement and a slide holder, the slide holder comprising: a sample chamber (33, 33', 33") including a gasket, said sample chamber (33, 33', 33") adapted to be mounted on said sample holder assembly fixture; a fluid reservoir (31, 31', 203) in communication with said sample chamber (33, 33', 33"); a first port (37, 37', 37", 38, 38', 38") in fluid communication with said sample chamber (33, 33', 33") via a fluid channel (36, 36', 36"); a second port (41, 41', 41"), separate from said first port (37, 37', 37", 38, 38', 38"), in fluid communication with said sample chamber (33, 33', 33"); and wherein slide holder includes a plurality of spaced clips each of which is adapted to be received and engaged in a respective cut out of the sample holder assembly fixture, and said spaced clips being configured to receive said sample substrate, wherein when said sample substrate is engaged in said sample holder, sample supported by said sample substrate is in said sample chamber (33, 33', 33"); characterized in that said fluid channel (36, 36', 36") is delimited by a region of the gasket (35, 35', 35", 401) included in said sample chamber (33, 33', 33") and in that said fluid channel (36, 36', 36") opens into said sample chamber (33, 33', 33") at an outlet opening (40, 40', 40"), wherein said fluid channel (36, 36', 36") and said outlet opening (40, 40', 40") are arranged such that, when fluid travels down said fluid channel (36, 36', 36") and out of said outlet opening (40, 40', 40") into said sample chamber (33, 33', 33"), the fluid fills said sample chamber (33, 33', 33") from the bottom up, thus reducing potential bubbles. a sample chamber (33, 33', 33") including a gasket, said sample chamber (33, 33', 33") adapted to be mounted on said sample holder assembly fixture; a fluid reservoir (31, 31', 203) in communication with said sample chamber (33, 33', 33"); a first port (37, 37', 37", 38, 38', 38") in fluid communication with said sample chamber (33, 33', 33") via a fluid channel (36, 36', 36"); a second port (41, 41', 41"), separate from said first port (37, 37', 37", 38, 38', 38"), in fluid communication with said sample chamber (33, 33', 33"); and wherein slide holder includes a plurality of spaced clips each of which is adapted to be received and engaged in a respective cut out of the sample holder assembly fixture, and said spaced clips being configured to receive said sample substrate, wherein when said sample substrate is engaged in said sample holder, sample supported by said sample substrate is in said sample chamber (33, 33', 33"); characterized in that said fluid channel (36, 36', 36") is delimited by a region of the gasket (35, 35', 35", 401) included in said sample chamber (33, 33', 33") and in that said fluid channel (36, 36', 36") opens into said sample chamber (33, 33', 33") at an outlet opening (40, 40', 40"), wherein said fluid channel (36, 36', 36") and said outlet opening (40, 40', 40") are arranged such that, when fluid travels down said fluid channel (36, 36', 36") and out of said outlet opening (40, 40', 40") into said sample chamber (33, 33', 33"), the fluid fills said sample chamber (33, 33', 33") from the bottom up, thus reducing potential bubbles.