2.2. PCR analysis
For DNA extraction, the fungus was grown in 100 mL of PD liquid
media for 48 h at 28 C. Fungal genomic DNA was extracted
from lyophilized mycelia using CTAB method (Sambrook and Fritsch,
1998). In order to confirm hph gene containing plasmid integration
into the host chromosome, transformants’ chromosomal
DNA was used as a template. Two pairs of PCR primers were used
to detect the insertion of the selective markers, hph gene (expected
with 650 bp) and amp gene (expected with 830 bp) in the mutants.
The forward primer 50-CAGGGTGTCACGTTGCAA-30 and reverse
primer 50-CTTCTGCGGGCGATTTGT-30 were designed and used
for hph. Whereas, forward primer: 50-CTTATTCCCTTCT TTGCG-30 ,
and reverse primer 50-CAATGCTTAATCAGTGAG-30 were used
for amp. Specific PCR fragments were amplified as follows: 95 C
for 3 min; 35 cycles of 94 C for 1 min, 56 C for 1 min; and
72 C for 1 min; then 72 C for 10 min. The PCR mix contained
1.0 lL of DNA template (1.0 lg lL1), 2.5 lL of 10 Taq buffer,
2.0 lL of dNTPs (10.0 mmol L1), 1.0 lL of each primer
(10.0 lmol L1), and 1.0 lL of Taq polymerase (5.0 Units lL1)
and topped to 25 lL volume by sterile super pure water
(Millipore, US).