Characterization of genes and gene products I

Which of the following are features of low stringency nucleic acid hybridization?

• low temperature

• high temperature

• lower salt concentration

• favor hybridization of mismatched sequences

• prohibit hybridization except complete complementarity

Why do we need an optimal annealing temperature in PCR?

• to denature double-stranded DNA into single strands

• to promote primer-DNA template hybridization without mismatch

• to allow DNA synthesis by heat-stable DNA polymerase while maintaining an intact structure

• to stabilize the hybrid structure for detection of unknown target sequences

• to maintain the stringency of hybridization between the DNA and the radioactive probe

Which of the following about quantitative real-time PCR (qPCR) is correct?

• Its main purpose is to detect the presence of target DNA in the sample.

• The Ct value would be lower if the amount of DNA in the sample in the start is greater.

• It utilizes reverse transcriptase, to convert complementary DNA (cDNA) into messenger RNA (mRNA).

• It is currently not applicable for Reverse transcription-polymerase chain reaction.

• The chance of contamination is extremely low.

Which of the following about characterization of protein is correct?

• ELISA can be used to localize the target protein.

• The difference between Immunohistochemistry (IHC) and Western Blot is that IHC only utilizes primary antibody.

• Western Blot gives a more precise quantitative analysis than ELISA.

• The enzyme-conjugated secondary antibody is in charge of giving out the detection signal.

• In Western Blot, primary antibody specific to the target protein is added to the gel in gel electrophoresis.

Give one significance and one limitation of PCR.