Deoxyribonucleic acid (DNA) is a distinct cell component, therefore DNA amounts are correlated with cell numbers (1). For example, in cartilage tissue engineering, artificial cartilage quality is evaluated by DNA amounts translated as chondrocyte numbers, as well as amounts of collagen and glycosaminoglycans (GAGs) in extracellular matrix components (ECM) (2, 3). DNA can be quantified by the ratio of absorbance at 260 nm and 280 nm. However, this method is affected by contaminating proteins, RNA and chemicals in the sample, thus requiring additional DNA isolation steps for accurate results. For tissue analysis, Chondrex, Inc. provides an alternative DNA assay kit employing the Hoechst 33258 fluorescent dye which specifically binds to Adenine-Thymine base pairs, resulting in fluorescence at excitation 360 nm/emission 460 nm. Since the dye-DNA binding and the fluorescence intensity are unaffected by contaminating proteins and other substances in an optimized assay condition, this DNA assay kit works accurately with samples containing other analytes.
Chondrex, Inc. also manufactures native collagen (type I, type II) detection assays, Hydroxyproline Assay Kit (cat# 6017), Sirius red/ fast green staining kit (cat# 9046 ), Sirius Red Total Collagen Detection Kit (cat# 9062) and Glycosaminoglycans (GAGs) Assay Kit (cat# 6022). These kits will facilitate further analysis of your studies.
DNA Assay Kit
|Product||Quantity||Catalog #||Price (USD)|
|DNA Assay Kit||1 Kit||6023||113.00|
Table 1 provides a useful matrix to determine the ideal solubilization protocol for the analyte of interest. In most cases, two different protocols will need to be used. For example, protocol A extracts GAGs, but fails to completely extract collagen and DNA, resulting in underestimated values (4,5). Protocol B solubilizes GAGs (6) and DNA (7), but degrades collagen. Finally, protocol C (Chondrex, Inc.’s protocol) can be used to measure GAGs and collagen (8), but not DNA. Please contact us if you have any questions about which protocol is right for your purposes.
1. V. M. Quent, D. Loessner, T. Friis, J. C. Reichert, D. W. Hutmacher, Discrepancies between metabolic activity and DNA content as tool to assess cell proliferation in cancer research. J Cell Mol Med 14, 1003-1013 (2010).
4. C. D. Hoemann, J. Sun, V. Chrzanowski, M. D. Buschmann, A multivalent assay to detect glycosaminoglycan, protein, collagen, RNA, and DNA content in milligram samples of cartilage or hydrogel-based repair cartilage. Anal Biochem 300, 1-10 (2002).