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Questions related from Xin Pin
I have seen COVID19 test LoD ranging from 180 to 600000 NAAT Detectable Units/mL So a rapid antigen test with LoD of TCID50 1.13 x10^2 per mL and RT PCR TCID50 1x10^-2 per mL (600 NDU/mL) and a...
29 November 2020 1,406 3 View
"Analytical sensitivity is defined as the concentration equal to N standard deviations above the zero calibrator. The most usual value for N is 2. To determine the sensitivity in this way, a zero...
22 May 2020 5,925 1 View
Why do we need all three salts in MOPS buffer? and PEG added to the reagent. NaCl crystalline 1.359 g/L KCl 0.708 g/L Ammonium chloride 0.0063 g/L KCL...
27 April 2020 6,226 4 View
I have attached the screen shot. In the table below It compares sequences between COVID-19, SARS-COV and Bat COV Mismatch numbers 11 and 9, meaning that COVID-19 compared to the other two...
31 March 2020 9,207 3 View
A competitive immunoassay technique is used. This involves the reaction of anti-HBc in the sample with hepatitis B core antigen (HBcAg) coated wells. Unbound material is removed by washing....
17 March 2020 10,048 3 View
The wells are polystyrene coated with streptavidin via a biotin BSA linking layer using the SAC well coating method. What is SAC coating method?
07 March 2020 3,152 3 View
WHO has established a reference preparation for hCG (currently the fourth International Standard, with an assigned content of 650 IU/ampoule) and a reference preparation for hCG-beta (currently...
31 December 2019 5,026 3 View
"The rate of point mutation in the V region is estimated to be about 1 change per 1000 base pairs per cell division, about 1000 times the rate of somatic mutation for non-Ig genes" Does it mean...
06 August 2019 5,963 3 View
According to a company they manf. Fast CAR-T cells in one day. Is it possible to transduce cells and expand them into millions within 24hrs? Assuming they used enhancers to transduce and...
06 May 2019 9,774 4 View
If a patient has been exposed to a particular type of AAV already, their immune system might have developed antibodies that could neutralize the effects of that vector. How do I know if a...
06 March 2019 922 6 View
454 GS FLX Titanium system which is capable of generating 700 megabase (Mb) of sequence in 700 bp reads. MiSeq reagents enable up to 15 Gb of output with 25 million sequencing reads and 2 ×...
18 October 2018 2,359 3 View
After reviving the cells from -80C and seeding the cells ~1 million in T25 flask when the cells reach 80% confluency then if I passage/subculture the cells for eg. spleen (finite) or CHO or...
20 July 2018 7,254 6 View
Protein PI 8.6 after Ni NTA affinity it is passed through Desalting column, desalting column equilibrated with pH 8 Tris eluted with tris then IEX (DEAE), IEX equilibrated with buffer pH 8 Tris...
13 April 2018 2,622 6 View
Spleen cells are fused with myelomas and therefore Hybridomas are immortal? although they exhibit ploidy they somehow (~1%) manage to survive. Eventually they reach senescence and perish after...
29 January 2018 9,949 1 View
Does CRISPR-Cas9 completely replaces the use of Site-directed mutagenesis? what are pro and cons for each?
23 December 2017 9,554 3 View
"The “flow cell” is the place in the cytometer where the sample stream is injected into the sheath stream. After joining the sheath stream, the velocity of the cell suspension (in meters per...
13 November 2017 2,030 1 View
In western blot why do we dilute primary antibody in 1% skimmed milk so that if there are any antibodies against blocking agents they get blocked? but why would they be antibodies against skimmed...
04 November 2017 2,011 7 View
I noticed so much inconsistency in the indirect ELISA for cell culture supernatant and also for purified MAbs. Although some clones follow serial dilution say 2-3 out of 8 clones on the same...
31 October 2017 8,271 3 View
If I have 2.8*10^6 cells (2,800,000) and I set up serial dilution as follow 10ul from the above + 90ul medium (100ul = 280,000) 10ul from the above + 90ul medium (100ul = 28,000) 10ul from...
29 October 2017 3,931 7 View
Rabbit monoclonal antibodies "recognition more diverse range of epitopes" what does diverse range of epitope mean? Eg. I have hybridoma clones all secrete identical antibodies against single...
07 October 2017 7,217 5 View
Why do they refer protein oxidation as Chlorination, Nitration?In general, oxidation is the loss of electrons/Hydrogen and the gain of oxygen.How does Chlorination (addition of Cl) or Nitration...
02 October 2017 1,718 6 View
The definition of 1 unit is "The amount of enzyme that will incorporate 10 nmol of dNTP into acid-insoluble material in 30 minutes at 75°C." If I have to perform a unit assay does my enzyme has to...
04 September 2017 6,944 5 View
What is the correct way of choosing competent cells (cc) volume during cc preparation (58ul cells + 2ul plasmid) based on cc concentration or ration? NEB recommends required ration is 1:25 and...
03 September 2017 3,652 9 View
While counting cells with hemocytometer trypan blue exclusion should I calculate both the chamber (two counting grids) 5 square in each chamber? or only one chamber? Each square occupiers 10^-4 ml...
01 September 2017 5,986 6 View
"Primer Melting Temperature (Tm) by definition is the temperature at which one-half of the DNA duplex will dissociate to become single stranded and indicates the duplex stability. Primers with...
31 August 2017 5,144 15 View
The procedure involves lysis of nuclear membrane and bind DNA on to the column. But DNA is tightly packed with histones as chromosomes are we disassociating DNA from histones? or extracting...
29 August 2017 9,602 5 View
DEAE has a pKa 6.9 (DE52) Tryptophan synthase, alpha subunit has pI 5.31 Wash buffer & Equlibriation buffer are same pH 7.8 (10mM phosphate buffer 4mM Na2EDTA 1mM DTE). Pellet fraction...
26 August 2017 8,143 10 View
