The quality of miRNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue by duration of storage (11 year intervals) and three tumor tissue types (n = 118).

<p>The quality of miRNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue by duration of storage (11 year intervals) and three tumor tissue types (n = 118).</p

Box and whiskers plots showing the distribution of absorbance ratios (A_260/280) for nucleic acids DNA, RNA, miRNA and for protein (A₂₈₀) from FFPE.

<p>Panel A shows derivatives from FFPE stored between 1990–2001 and Panel B derivative from FFPE stored between 2002–2013 stratified by storage duration (11 year intervals) and cancer tumor tissue type (adenocarcinoma, squamous cell, and papillary carcinoma).</p

Matrix of Spearman correlation coefficients between the numbers of failed derivatives in any set of two molecular extracts from the same block.

<p>Matrix of Spearman correlation coefficients between the numbers of failed derivatives in any set of two molecular extracts from the same block.</p

The fitness from formalin-fixed paraffin-embedded (FFPE) blocks tissue stratified by the storage duration (11 year intervals) and three tumor tissue types (n = 118) as categorized in Table 1.

<p>The fitness from formalin-fixed paraffin-embedded (FFPE) blocks tissue stratified by the storage duration (11 year intervals) and three tumor tissue types (n = 118) as categorized in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181756#pone.0181756.t001" target="_blank">Table 1</a>.</p

The quality of protein extracted from formalin-fixed paraffin-embedded (FFPE) tissue stratified by the storage duration (11 year intervals) and three tumor tissue types (n = 118).

<p>The quality of protein extracted from formalin-fixed paraffin-embedded (FFPE) tissue stratified by the storage duration (11 year intervals) and three tumor tissue types (n = 118).</p

Classification of FFPE block fitness as determined by the quality of nucleic acid and proteins derivatives.

<p>Classification of FFPE block fitness as determined by the quality of nucleic acid and proteins derivatives.</p

The quality of DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue by the duration of storage (11 year intervals) and three tumor tissue types (n = 118).

<p>The quality of DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue by the duration of storage (11 year intervals) and three tumor tissue types (n = 118).</p

Fit for genomic and proteomic purposes by steps (numbered yellow boxes).

<p><b>In step 1,</b> the ACCESS database of the ACSR at GWU was used to construct a sampling frame of available FFPE blocks by cancer case, which were the sampling units used to avoid selecting multiple FFPE blocks from the same individual. <b>In step 2,</b> the sampling frame of FFPE blocks was stratified by intervals of 11 years of storage (1990–2001 and 2002–2013, inclusive) and then the three tumor tissue types with the highest frequency of FFPE in the ACSR at GWU. Simple random sampling without replacement was conducted in each stratum until the targeted sample size of 20 FFPE blocks per storage duration and tumor tissue type was reached. <b>In step 3</b>, commercial kits were employed to extract nucleic acids and protein from 10 μm FFPE sections from each block; a separate FFPE section was used for each type of nucleic acid or protein extraction. <b>In step 4,</b> an initial assessment for the presence of the nucleic acid or protein was conducted by ultraviolet absorbance (UV). <b>In step 5,</b> the purity and concentration of nucleic acid and protein extracts were determined by a SpectraDrop Micro-Volume Microplate with a SPECTRAmax 384PLUS plate reader and SoftMax Pro v6.4.1 software for device control and data analysis. <b>In step 6,</b> nucleic acid and protein derivatives were assigned to fitness categories as described in the Methods section. <b>In step 7</b>, the fitness of each FFPE block was assessed by ranking the combined fitness of the derivatives as follows: FFPE blocks that met the “Fit Nucleic Acids and Proteins for Diverse Analyses” requirements included blocks in which all four derivatives (DNA, RNA, miRNA, and protein) were “Fit”. FFPE blocks that were categorized as “Fit Nucleic Acids for Diverse Genomic Analyses” included blocks that were determined to have “Fit” nucleic acid derivatives only. FFPE blocks that had one or two "fit" or "above fit" derivative out of the three nucleic acid derivatives and “unfit”, "fit" or "above fit" protein derivatives, were considered “Fit for a Specific Genomic or Proteomic Analysis”. <b>In step 8,</b> if an FFPE block had no “Fit” molecular derivatives, it was considered a “Bad Block”.</p

Box and whiskers plots showing the distribution of concentration (nanograms per microliter) for the nucleic acids DNA, RNA, and miRNA co-extracted from FFPE.

<p>Panel A shows derivatives from FFPE stored between 1990–2001 and Panel B shows derivative from FFPE stored between 2002–2013.</p

The quality of RNA extracted from FFPE by duration of storage and tumor tissue types (n = 118).

<p>The quality of RNA extracted from FFPE by duration of storage and tumor tissue types (n = 118).</p