Question about Tasco 750 Monocular Microscope

2 Answers

Problems with viewing under low magnification (20x) only red stain

I was looking at cells under low magnification (20X) and noticed that
if I tried to view my stain on these-- dapi, rhodamine; the dapi worked
fine,light seemed to be aligned correctly. However, the red stain did not
show. It appears the light path is blocked -with two circles meeting half
way cancelling each other. This only happens and is the most obvious under
low magnification and with the red stain. If I try to view this with 60X,
I am able to get some of the red, however, you also see a halo - a part of
the field of view with bright light coming through. This is just a recent
development as I had no such problem last week.

So, my question to you, what could be causing this and how can I fix
Any help or advice would be greatly appreciated.

Thank you so much for you time.

Posted by on


2 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert who has answered 20 questions.


    An expert that hasĀ over 10 points.


    An expert whose answer gotĀ voted for 2 times.

  • Contributor
  • 30 Answers


Sounds like you are using a Phase Contrast Microscope to me, and if this is the case, you will get just this kind of result, especially if it is not set-up correctly.
Let me have the make and model, and I will happily talk you through this one.

Kind Regards......Dave

Posted on Mar 10, 2008

  • Level 1:

    An expert who has achieved level 1.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 7 Answers


For the red colour partical your illumination angle should be 0 degree.
As per you exepirience you are getting red at low magnification and not getting at high magnification. at the higer magnification the light deviation you can apriciate more then lower.

try to adjust your light source focusing lenc at higher magnification so at the lower it will be more better,

for the further problem you can contect me any time,



Posted on Feb 20, 2008


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Im having trouble with my drives it wont read the cd or burn the cd or dvd

Hello there,

If your LG SecurDisc 20x Internal Double-Layer DVD RW/CD-RW Super Multi Drive w/LightScribe does not read disc, burn cds or dvd, then it means there is a problem with the lens of the LG SecurDisc 20x Internal Double-Layer DVD RW/CD-RW Super Multi Drive w/LightScribe.

You will have to replace the LG SecurDisc 20x Internal Double-Layer DVD RW/CD-RW Super Multi Drive w/LightScribe or have the lens replaced.

Be sure not to use the LG SecurDisc 20x Internal Double-Layer DVD RW/CD-RW Super Multi Drive w/LightScribe to watch movies as that weakens the lens easily.

Hope this helped.

Aug 09, 2011 | LG SecurDisc 20x Internal Double-Layer DVD...

2 Answers

After turning of the TV for a few minutes, it won't turn ON. The power LED turns green for a second and then becomes red and flashes, Philips Model 32PF7321D/37

grodmx74, You or electronics technician will need to find the "thermally-intermittant-hair-line-fracture" of a component soldered to the switch-mode-power-supply printed circuit board with aid of large magnifing glass or use a 10x or 20x inspection microscope, and then resolder the connection. 12fixlouie

Apr 02, 2010 | Philips 32PF7321D 32 in. LCD Television

1 Answer

Media player classic says "cant find dvd directory" when i put in a movie dvd?

try downloading VLC player
It is free, and it plays almost every video format

Nov 14, 2009 | Lite On LiteOn LH-20A1P - Disk drive -...

2 Answers

The drive door stays open on the dvd recorder drive after attempting to close it. the drive will not read the cds. it opens up without depressing the button.

try to read carefully the description of your dvd-r may only read dvd format and not cd. their are drive indecates to reads dvd-Rw and also cd-reader.

Nov 05, 2009 | Lite On LiteOn LH-20A1P - Disk drive -...

1 Answer

Need 80mm eyecepie,for swift spotting scope #821.


Sep 07, 2009 | Swift Optics

2 Answers

Can stained bacteria be seen with a 40x magnification microscope? not in detail, just enough to determine coloration of individual bacteria

Hello--I understand that you need at least 600x to view bacteria and some say 1500+ so 40x doesn't seem to be in the right mag. area at all--not sure this helps much.You could purchase a 100x obj. and 10/15x eyepieces but will probably be into oil immersion for the obj.Possibly a 20x eyepiece + a 60x obj will give you a degree of definition.I use a SEBEN Bino with this combi and it gives a small view but not good.kind regards martin r

Nov 13, 2008 | National Optical 131 Monocular Microscope

4 Answers

Cd audio can hear but no dvd audio

First check that the 'Wave' slider in the volume control is not too low or muted.

Check in the DVD player software that you have the correct DVD audio stream selected.

Then suspect the audio codec that should have been installed with the DVD player software.

Oct 21, 2007 | Lite On LiteOn LH-20A1P - Disk drive -...

6 Answers


Hi there,

Seing bacteria isn't just about magnification, many
are transparent and need to be stained. Even at X1000, you will see little detail, but can make approximations of shape etc. Here is a good starting point for staining bacteria.
With a toothpick scrape a little plaque from your teeth (size of a pinhead is plenty). Put this in the centre of a slide with 1 drop of water and mix thoroughly. Allow this to dry then pass the sample through a flame three or four times (hot, but not hot enough to burn fingers) Stain for five mins using either Methylene Blue or Eosin. If you don’t have these, Blue or Red fountain pen ink will do for starters. Rinse off excess stain with very slow running water. Blot dry and observe at X400. If you have an oil immersion lens, you must use a cover slip and mount your specimen in balsam first.
If I can be of any further help, please don’t hesitate to ask.

Aug 01, 2007 | National Optical 131 Monocular Microscope

Not finding what you are looking for?
Tasco 750 Monocular Microscope Logo

Related Topics:

145 people viewed this question

Ask a Question

Usually answered in minutes!

Top Tasco Science & Laboratory Experts


Level 3 Expert

5620 Answers

 Brian Main
Brian Main

Level 3 Expert

467 Answers

William McMath

Level 2 Expert

178 Answers

Are you a Tasco Science and Laboratory Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides