Can natural frequncies of vibration be complex?

I want to calculate first six natural frequency of rectangular plate but it gives me complex value.

02 March 2019 3,711 16 View

Waters 2707 HPLC autosampler problem?

I am using a 2707 waters HPLC device. When I try to inject a sample, it says missing plate or rack. I changed the needle and calibrated its position but I still get the same problem. I even get...

02 March 2021 1,408 1 View

Should we change media after1st 6hrs after plating HUVEC bought from INVITROGEN?it's not recomended by invitrogen.Will DMSO present in stock matter?

We have HUVEC bought from Invitrogen. Cat no -C-003-5c. while first plating the cells we have bought the protocol suggests not to centrifuge the cell with media to remove the DMSO. Should we...

02 March 2021 3,713 2 View

How to normalise data on OPM package from R Studio ?

Good afternoon, I recently used OmniLog from BIOLOG for my experimentations : I tested the metabolism of different strains on 2 types of plates. I have 16 strains of 3 different groups...

02 March 2021 3,584 1 View

Benefits of the 24 welled plate?

We have always used the 96 welled plate, the 48 welled plate but apparently there is much evidence on the 24 welled plate and above all its benefits.It states it is the same you would use on ELISA...

28 February 2021 1,149 1 View

Can bacterial suspension be pipetted directly onto petri dish and agar poured onto it?

Hi, recently I encountered a protocol for plating which was not the usual method I have been practicing (pour LB agar onto plate, allow it to solidify, pipette bacterial suspension onto plate,...

28 February 2021 7,292 3 View

What is the best surface to culture cells isolated from a skin biopsy?

Hello, recently I am having some difficulties with maintaining the cell culture of primary cells isolated from a skin biopsy (normal and malignant). The coating of culture plates with Matrigel (a...

26 February 2021 6,151 2 View

Difficulty in cloning of 1kb gene into vector?

I am facing difficulties in cloning a 1kb gene into a vector (pJIT163). I have my gene on interest (GOI) in pUC57 and want to clone in pJIT163 using SalI and BamHI restriction sites. I am getting...

25 February 2021 3,221 7 View

Can cells be reused after using WST 8/ CCK 8 from Sigma Aldrich?

Hi all, Can cells be reused after I have seed them onto 96 well plates and test them with cell counting kit at OD450 (CCK8) at 12 hours, wash them with PBS x3 and add new media and let them...

24 February 2021 5,072 1 View

Standard curve shifting over time. How do I stabilise the ELISA?

24 February 2021 1,365 3 View

What is the standard protocol in doing replicates for C. elegans lifespan assay on solid media (thru worm picking)?

I would like to know what is the standard protocol in the number of worms per plate and number of plates per concentration of extract X in a lifespan assay done in solid media and not automated...

23 February 2021 9,933 1 View