16S rRNA gene of gram positive cocci (11 isolates) were extracted and amplified by
using universal primer. These fragments of each species were cloned in plasmids and
preserved as clone libraries. Plasmid DNA was amplified by using M13 primer and PCR
product used as DNA template to blot on a nylon membrane. V6 region in 16S rRNA gene of
Streptococcus pneumoniae was amplified by PCR using digoxigenin-11-dUTP. PCR product
was an initial experimental probe to optimize conditions of the hybridization with the
reference DNA blotted on nylon membrane. Various anneal temperature and concentration of
SSC buffer were tested to determine optimum hybridization conditions based on visual
observation by using anti-DIG-AP conjugate, CDP-StarTM.