Cool!
So basically you claim that hypoxia (low oxygen) condition is not created, as the containers were broad mouthed and not plugged. btw, I believe cotton plugs donāt make it air tight, and still allow oxygen transfer! That is the reason fruit fly culture use them.
Is there a way to estimate the effect of this? Does it depend on the area of water surface exposed or area of the mouth of the container!
Does anyone any idea?
-DP
@drishtantmkawale Does this thread have an answer? The title suggests so! You too seem to have taken part in it.
-DP
Correct! And I agree to you too that cotton plugs do not make it airtight and will allow oxygen transfer. That is why it is preferred to wear cotton clothes in summer! To allow passage of air! 
If we think logically or even visualise the broad mouth of the cups and the narrow mouth of the bottles, there is a considerable difference in both.
Even though cotton-plugged, can we not say that air-passage in the bottles will be comparatively less than that of the cups?
In addition to this, 4 and 6drops of milk was added on alternate days in two of the test cups. A ~24hour time period would be enough for the oxygen-level rise.
A way to estimate the effect of what @karnamdpdurga? (Sorry for missing it)
It will depend on both; the area of the water surface exposed as well as the area of the mouth of the container.
The first point of entry of air will be the mouth of the container and then the surface of the water.
Sir please send the link of todayās class
CUBE Nerul Home Lab
Moina Model
Summary of the experiment with Moina.
Objective: To observe a colour change in Moina when they are kept in low-oxygen conditions.
Date of Setup preparation: 14th Oct 2020
Result: The objective wasnāt achieved according to the expectations. The expectations were to observe the first colour change in Moina [kept in the cups having 250mL of dechlorinated water+6drops of milk (on alternate days)] on the third day i.e. on 17th Oct. But no colour change was seen in Moina.
Below is the link of the video from the 3rd day.
https://drive.google.com/file/d/1hgg8cKph8Ja0rPe4Sj4TLcGAQXm03ryt/view?usp=sharing
No colour change was seen in Moina from all the test cups and the control Moina remained colourless.
Meanwhile no colour change was seen, number of Moina in the cups increased as well as decreased i.e. they followed a growth curve.
The above growth curve [X-Axis: number of days from 14th to 28th Oct, Y-Axis: number of Moina in all (8) the cups aggregate] tells us about different phases of growth of Moina.
From 14th to 16th Oct, the number of Moina remained constant more or lessā> Lag Phase.
From 17th to 23rd Oct, the number of Moina increasedā> Exponential Phase.
From 23rd to 25th Oct, the number of Moina remained constantā> Stationary Phase.
From 25th Oct till now, the number of Moina has been decreasing that marks the onset of death phase.
This growth curve is more or less similar to a bacterial growth curve.
Explanation of the observations:
As there was no colour change seen in Moina from any of the test cups at any point (totally opposite of what was expected), I think there are two reasons for this both because of an improper design of the experiment.
i) The design had 8 cups in total that were divided into 4 sets of two each. Control and Test1 cups were added with 1 and 2drops of milk daily. The Test2 and Test3 cups were added were 4 and 6drops of milk on ALTERNATE DAYS.
This is where the devil was, I think. As the expectations were to observe the first colour change in 6drops of milk set on the 3rd day (17th Oct), milk shouldāve been added everyday so that a low-oxygen condition wouldāve been maintained. But as 4 and 6drops of milk were added on alternate days, the low-oxygen condition didnāt sustain. In addition to this, the cups have a broad mouth and were covered with a cotton cloth, oxygen kept on diffusing in the water due to which the dissolved oxygen level of the water didnāt really decrease till such an extent, where Moina wouldāve started the production of extra-haemoglobin.
That is why the test Moina appeared colourless throughout.
ii) The expectations of observing a colour change in Moina (from the test cups) on the third day were not of this experiment. This can be expected when 6drops of milk are added in 250mL of DC water daily and not on alternate days. Also, in the same experiment, plastic bottles having a narrow mouth plugged with cotton were used. Plastic bottles having a narrow mouth and plastic cups having a broad mouth do make a difference in the giving entry to oxygen inside. Here, the difference that was seen was the bottles having Moina+water+6drops of milk daily, colour change was seen on the third day whereas we saw no colour change in this experiment.
GOOFUP:
Not designing an experiment with proper test sets.
This improper design of the experiment with expectations from another experiment led to an unexpected outcome of this experiment!
I learned that while designing an experiment like this, we should keep in mind the smallest of things such as the size of the container, the drops of milk that are being added and whether expectations are according to the setupā¦
Celebration:
Learning from the above goofup, another design of the experiment has been planned, this time with proper test sets.
Keeping in mind the expectation of observing a colour change in Moina, this experiment will give results.
The design will be shared later tomorrow.
Till then, everyone please suggest improvisations on the design.
Can we approximate from the image that moina is around 1mm long?
Yes we can!
In the earlier posts, photos/videos of Moina with a ruler (scale) beside have been posted.
CUBE Nerul HomeLab
Moina macrocopa JSK1 Model System
Breaking News
Two bottles full of Moina!
Research Question: Why do Moina undergo a colour change when subjected to low oxygen conditions?
Long-term objective: To study the effect of histone deacetylases-inhibitor Valproic Acid on the colour of Moina due to Haemoglobin protein.
Objective: To culture and maintain Moina in the HomeLab.
https://drive.google.com/file/d/1TaTXfFOMR-vGGNvF4z3zk_uE9-fPbb_n/view?usp=sharing
The above video shows ~150 colourless Moina in two of the culture bottles L4 and L5.
Currently, there are five culture bottles L1 to L5 having 250mL of dechlorinated water, 1 drop of milk is added daily and 5 Moina were added initially.
L1 to L3 made on 1st Jan 2021 and L4, L5 were made on 12th Jan 2021.
Date of Video: 19th Jan 2021
Place: Nerul, Navi Mumbai, MH
Taken by: Drishtant MK
Achievement so far: I alongwith my collaborator CUBists have successfully cultured/been culturing Moina since the lockdown started i.e. for almost 300+ days now!
Our CUBists @manmasih @Manjuel, @Rechel_tirkey @Ram (from Ranchi, JH) and Abhijith Vinod (from Kolenchery, Kerala) have been culturing Moina in their HomeLabs even before the start of lockdown!
Let us continue this stint for the time to come!
First step would be updatesā¦ followed by discussion.
Looking forward to hear from you alongwith updates
@Zahra_R17 @saida786110 @saswathy679 @arunimakunju99
@drishtantmkawale Thank you for narrating all the experiments and results in such an amazing fashion. It is really very exciting and interesting. 
CUBE Nerul Homelab
Moina Model System
Breaking News
Moina fit and fine all throughout an ~3000kms journey down-south!
Above is the map of my 15day journey wherein I took alongwith me the model organism Moina macrocopa JSK1 and was successful in maintaining them throughout with fewer hiccups wrt. culturing, etc. and the journey involved shifting my Nerul homelab to temporary Car and Train homelabs too!
Two 500mL bottles having 250mL of DC water + ~30 Moina each were taken along out of which Moina survived in only one of the bottles. Their feeding pattern wasnāt fixed as a result of which 1drop of milk was added just four times in 15days.
When I returned back, ~30 Moina were remaining in the bottle (that was taken along) out of which I made two new bottle cultures.
Video
And here I am updating after quite sometimeš
Above is a video showing movement of Moina alongwith alot of Rotifers accompanying them in the 250mL DC water and are fed with 1drop of milk on alternate days.
Date: 8th April 2021, Thursday
Place: Nerul, Navi Mumbai
Video by: Drishtant MK
Interesting CUBE Chat here! Good record of all your observations!
How do we calculate the size of an organism or anything that we observe under a microscope?
Context2Curriculum! Moina model system or any other model system ā connected to microscopy.
All the collaborative stuff here!
Iāll share my experience of calculating the size of Moina. I bought a laser light (red-coloured one used in presentations, etc.) and took the lens (convex) out of it.
Steps
i) I attached this lens to the rear camera of my mobile phone (via a stick tape).
ii) Further, I harvested Moina out of my stock culture through a dropper and placed a few of them on a glass slide.
iii) Held a light source (another phoneās torchlight) below the glass slide.
iv) Simultaneously, I also placed a ruler scale under the glass slide as a reference scale.
v) Click! 
Took a photo from above by doing the required adjustments. No digital zooming was done.
Well, this is not it . Weāll have to process the image to measure the approximate length/size of the organism.
That can be done by using the ImageMeter application for mobile phones.
Hereās the link to a video that will introduce you to the app.
Results
) juvenile
The pictures may not be resolute and clear but I am improving upon that.
All of it will be possible when collaborators will try it out in their homelabs and give feedback whether it worked out there.
Rest, I think this inexpensive jugaad can be used for every model system in CUBE provided that a reference scale and a bit of meticulousness is maintained while doing it.
What do you say? @Lydia
This is great!
Maybe, you can share a ray diagram kind of to show how the whole setup looks.
What we can also do is, we can share this with our collaborators and they too can follow this. We need to get reproducible results with the help of our collaborators. The size of different model systems can be measured using this method.
Iām not sure if everyone has a laser light lens in their house. Is there by any chance, an alternative for this one component?
Yes agreed!
There is an alternative, but its an expensive one
Some YT videos suggest the lens CD-DVD reader (the centrepiece in the picture below)
One can use the above lens if they have a damaged DVD player.
Apart from this, Iāll prefer that you should look for this laserlight lens which cost me Rs.60 (after alot of bargain. Eventually I was going to break it 
).
Less than a $ itāll cost usāall!
@ravi312 had come up with this interesting thread. Do give a visit 
Yes, this is surely an alternative, but only if itās a damaged one. Otherwise, definitely not a new, and expensive one.
A cheaper alternative is preferred or something that we already have in our house
DP is into plotting.
Hi i am sakshi beloshe from N.E.S ratnam college i am also maintaining moina culture as a feed for hydra.
The question was why canāt we use that curd to feed moina because it also contains bacteria or you can say more bacteria than milk???
So why milk??? Why not curd??
Hello sakshi!
Itās a good question. So when we discuss about culturing Moina in Homelab or college lab it is easier to convey it to people that you can culture it with milk. Every household has milk. So mostly we say milk. You can also used curd but make sure you only use the water of the curd and not the lumps otherwise those lumps will settle down and you have frequently clean your culture. Even i used curd water when I donāt have milk someday.
So you can try and let us know if you how it worked!!
