Uma Nudurupati

9 Questions 28 Answers 0 Followers

Questions related from Uma Nudurupati

2695 Alliance error: Column temp h/w fault (5): how to resolve?

I have been encountering the error "Column temp h/w fault (5)" on a 2695 Alliance. I tried to ignore the alert and run a diagnostic test on the column heater. 5 seconds into the diagnostic test...

27 May 2020 4,194 0 View

Need help trouble shooting veeco 3100 Dimension AFM : Cantilever won't tune ?

I am trying to tune the cantilever HQ:NSC19/NO AL ( https://www.spmtips.com/afm-tip-hq-nsc19-no-al ) on the 3100 SPM Dimension. The manufacturer's suggested resonance frequency is 65 kHz (25-120...

14 November 2019 8,129 1 View

BCA Assay trouble shooting: why is analyate's estimated conc 40% of expected value?

I have been trying to estimate the concentration of collagen type II (tripeptide) in 0.012 M HCl using BCA Assay. I denature the aliquot of protein sample I use by heating it to 60 degrees...

25 March 2019 6,868 9 View

What is the best way to study acid soluble proteins under various buffered conditions?

I need to perform fibrogenesis study of an acid soluble protein (Collagen type II) using turbidity measurements. I have been looking through the literature for an efficient way to prepare the...

26 February 2019 7,883 0 View

How to confirm contact with the material in rheology? What is the role of normal force?

I have a hydrogel of thickness ~ 4000 um and I want to perform a frequency sweep on it. How do I know that the plate is in contact with the material apart from visually seeing it in contact? I...

23 January 2019 8,361 2 View

How do you choose the wavelength at which turbidity has to be measured?

I have been looking into turbidity measurements in different contexts, and I find that turbidity is measured at various wavelengths depending on the experiment. For example, for bacterial growth...

19 December 2018 7,892 2 View

How to remove MEHQ from Methacrylic acid monomer without reduced pressure distillation?

I am aware that the standard way to remove MEHQ from Methacrylic Acid is to perform reduced pressure distillation. The papers I see suggest using ~ 10 Torr pressure to perform distillation....

23 October 2018 9,824 12 View

TA instruments Rheometer AR 2000: How to change geometry gap for a parallel plate?

I am trying to perform rheology experiments on a cross-linked polymer gel to measure its shear modulus (G) and its G' G" response to an oscillatory stress on an oscillatory rheometer. My polymer...

01 June 2018 1,261 5 View

What is a good free thiol standard for a thiol estimation assay (in the uM - nM range) ?

I am looking to estimate the free thiols in my Polymer using the NTSB assay ( Thannhauser et. al. , Methods in Enzymology, 143 , 115 – 119) . In this assay the chromophoric agent is NTB which...

22 May 2018 2,989 8 View