pack 5 Flashcards
(21 cards)
What are the types of PCR?
End point/Conventional PCR
Simple +/-
Real time / quantitative PCR
Either quantitative or relative
What are two rules that we use to interpret PCR?
The results should be of expected size
No product should be in the reagent blank
Explain the difference between the blank and the negative
The blank is a tube that contains everything needed for the PCR except the DNA (Primer, Taq polymerase, dntp mix)
The negative is a tube that contains everything including DNA, but the DNA is not infected with the virus
What is the relation between the amount of DNA and the threshold cycle in quantitative PCR?
The amount of DNA is inversely proportional to the threshold cycle
Is specimen 2 not affected? Explain
Not nessceraliy, bc of the fact that the B-Actin test came back as negative, we can conclude that the sample wasn’t properly taken and the test should be re done
What is the difference between the amount of DNA present in the first (leftt) and last (right) samples? Explain.
The amount of DNA present is greater in the first than the last bc as we know the amount of DNA is inversely proportional to the amount of cycles
What is SYBR green and what does it bind to?
It is a dye that only binds to double stranded DNA
go back to taq man
What are the two types of COvid 19 tests?
Diagnostic (to see if the patient is currently affected)
Seralogical (to see if the patient was ever infected)
WHat are the two types of diagnostic covid 19 tests?
Molecular test: Detect the genetic material of the virus (RNA)
Antigen: Detect the proteins/antigens found on the surface of the virus
What is the difference between sensitivity and specifity?
Sensitivity: Better at detecting the disease (less false negatives)
Specifity: Better at detecting a normal person (less false postive)
Compare and contrast antigen and molecular diagositic testing for Covid 19
molecular: More specific and more sensitive (used in hospitals)
======================
antigen: Simpler but is less sensitive
What type of test is used for antigen testing?
Sandwich ELISA
What type of test is used for molecular diagnostic covid 19 testing?
RT-PCR
What are some applications of PCR that are related to fetuses?
Prenatal testing for defects
Preimplantation genetic testing
What does ddnmp do?
It terminates elongation
What is sager sequencing?
A DNA sequencing technique
- Four different tubes that contain the DNA with a radiolabeled primer specific for the 3’ end
- Each tube has a dNTP mix
- Each tube also has one of the four dideoxy ribonucleoside triphosphates (ddNMP) (specific for each letter)
- It is then run through gel electropherosis to get results
How do you extract the sequence from this card?
You read it from bottom to top
Sequence: GCTGTTAGAATGT
Sanger Sequencing V.S Next-Generation sequencing (NGS)
- Sanger sequencing can only sequence one DNA fragment at a time
- Next-generation sequencing can do multiple DNA fragments at once
ًWhat can microarrays detect?
Can profile gene expression levels of THOUSANDS OF GENES simultaneously
- Able to detect single nucleotide polymorphisms (SNPs)
