METHODS: In this study, mouthwash, saliva, and buccal cytobrush samples were collected from β-thalassemia major patients who had previously been characterized using DNA extracted from peripheral blood. DNA was extracted from mouthwash, saliva, and buccal cytobrush samples using the conventional inexpensive phenol-chloroform method and was measured by spectrophotometry for yield and purity. Molecular characterization of β-globin gene mutations was carried out using the amplification refractory mutation system (ARMS).

RESULTS: DNA extracted from mouthwash, saliva, and buccal cytobrush samples produced high concentration and pure DNA. The purified DNA was successfully amplified using ARMS. Results of the β-globin gene mutations using DNA from the three non-invasive samples were in 100% concordance with results from DNA extracted from peripheral blood.

RESULTS: The lysis buffer 2 (LB2) has been shown to be the best lysis buffer for DNA extraction from both raw and processed meat samples comparing to other lysis buffers tested. Hence, the LB2 has been found to be ideal to detect meat and porcine DNAs by real-time PCR using pairs of porcine specific primers and universal primers which amplified at 119 bp fragment and 93 bp fragment, respectively. This assay allows detection as low as 0.0001 ng of DNA. Higher efficiency and sensitivity of real-time PCR via a simplified DNA extraction method using LB2 have been observed, as well as a reproducible and high correlation coefficient (R2  = 0.9979) based on the regression analysis of the standard curve have been obtained.