Thermo Scientific Invitrogen Countess 3

Questions and Answers

N
nwilliamsAug 2, 2025
Why does the Thermo Scientific Invitrogen Countess 3 Cash Counter count live cells as dead?
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  Crystal SantosAug 2, 2025
  If the Thermo Scientific Cash Counter counts live cells as dead, several factors could be at play. First, ensure the cells are correctly focused, so live cells have bright centers, and dead cells are dark throughout. If cells are well-focused with bright centers but still counted as dead, check that they are within the appropriate size range and adjust the settings. Also, if cells are exposed to trypan blue for too long, viability could be affected. Finally, optimize capture settings by gating out debris using the size, brightness, and circularity sliders.
K
Kimberly CrawfordAug 6, 2025
How to include all cells in the count on Thermo Scientific Invitrogen Countess 3?
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  joshuareedAug 6, 2025
  To include all cells in the count on the Thermo Scientific Cash Counter, adjust the settings. For brightfield cell count and cell viability assays, modify the size, brightness, and circularity gates for both live and dead cells. For fluorescence assays, adjust the size, brightness, circularity, and fluorescence intensity gates in all available channels. Ensure channels are optimally illuminated in both brightfield and fluorescence modes (only in Countess™ 3 FL Automated Cell Counter). When the gates are fully maximized, the CSV should indicate 0–70 for cell size and 0–255 for brightness. After including all of the cells in the count, you can narrow the count criteria to exclude cells of a certain size or brightness.
P
Paul WalkerAug 10, 2025
How to fix the error when updating the Thermo Scientific Cash Counter software?
- E
  Eric DorseyAug 11, 2025
  To resolve issues updating the Thermo Scientific Cash Counter software, ensure the USB drive is formatted to FAT32. The update file should be at the root of the USB drive, not in a folder, and the file must not be renamed, zipped, or compressed; it must be uncorrupted during transfer and have a .lft suffix. If needed, check that the USB port is functional by testing a USB mouse.
J
James KnightAug 14, 2025
Why am I getting variable counts for the same sample of cells using the Thermo Scientific Cash Counter?
- R
  Regina JacksonAug 14, 2025
  Variable counts for the same cell sample on the Thermo Scientific Cash Counter can be attributed to incorrect pipetting or mixing. Use recently calibrated pipettors, and ensure the cells are well suspended by pipetting up and down several times before adding trypan blue.
D
Donna ThomasAug 19, 2025
What to do if the Thermo Scientific Cash Counter shows an incorrect concentration for the test beads?
- S
  Sandra HarrisAug 19, 2025
  If the Thermo Scientific Cash Counter shows an incorrect concentration for the test beads, it may be because the beads settled quickly in solution. Vortex the bead stock on high for 30 seconds to resuspend, and add 10 µL of the bead suspension to 10 µL of trypan blue without delay. Pipet the bead and trypan blue mixture up and down several times to make sure it is well mixed and immediately load 10 µL into the slide.
E
estradabrandonAug 23, 2025
Why are there variable counts when performing replicate counts of the same slide on the Thermo Scientific Cash Counter?
- U
  ufrazierAug 23, 2025
  Variable counts when performing replicate counts of the same slide on the Thermo Scientific Cash Counter can occur if the slide was mishandled or viewed differently multiple times. Visually inspect that all cells are counted correctly in the image. There may be a slightly different field of view each time a slide is inserted. Count cells at a higher concentration to reduce variability. Make sure you do not shake or agitate the slide between counts.
K
kathrynleeAug 27, 2025
What to do if Thermo Scientific Invitrogen Countess 3 does not recognize the USB drive?
- T
  Tanya FlynnAug 27, 2025
  If the Thermo Scientific Cash Counter does not recognize the USB drive, the USB drive must be FAT32 formatted. If it is not, reformat the USB drive to FAT32. Try another correctly formatted USB drive.

Summary

Product Information

Product Description

Details the Countess™ 3 Automated Cell Counter, its features, and capabilities for cell analysis.

Instrument Receiving and Setup

Instructions for inspecting the instrument upon arrival and its initial setup procedures.

Instrument Registration and Parts Identification

Guidance on registering the instrument and identifying its external components.

Instrument Installation and Configuration

Operating Environment Requirements

Specifies optimal conditions for instrument placement, temperature, and humidity.

Instrument Installation and Power On Procedure

Step-by-step guide for unpacking, setting up, and powering on the instrument.

Connect Account Setup and Login

Procedures for setting up a new or logging into an existing Thermo Fisher Connect account.

Custom Templates for Cell Counting

Template Management and Functions

Overview of the Templates screen, including creating, editing, importing, and exporting templates.

Count Parameter Adjustment

Details on adjusting gating parameters like size, brightness, and circularity for cell counts.

Loading and Using Templates

Steps for loading, creating, and editing custom templates for consistent cell counting.

Cell Counting Slide Preparation and Loading

Sample and Slide Preparation Recommendations

Best practices for preparing cell samples and slides for accurate counting.

Loading Cell Counting Chamber Slides

Detailed instructions for preparing and loading disposable Countess™ cell counting chamber slides.

Loading Countess Reusable Slides

Procedure for preparing and loading the reusable Countess™ glass slide for cell counting.

Performing Cell Counts and Viability Assays

Brightfield Cell Counting Procedure

Steps for capturing and counting cells using brightfield illumination and auto-focus.

Analyzing Assay Results and Next Steps

Guidance on interpreting results, viewing histograms, gating, and next actions after a count.

Identifying and Gating Cells in Results

Methods for marking live/dead cells and adjusting count parameters using gating features.

Saving Custom Templates from Results

How to save adjusted count parameters as new templates after performing a count.

Instrument Calculators for Dilution and Splitting

Pre-Dilution Calculator Usage

Tool to calculate the necessary sample dilutions before loading for cell counting.

Cell Splitting Calculator Usage

Tool to determine sample and buffer volumes for achieving a desired cell concentration.

Saving and Exporting Experiment Data

Saving Experiment Results and Options

Overview of saving options including results, images, reports, and CSV or FCS files.

Step-by-Step Data Saving Procedure

Detailed steps for saving experiment data to USB drive or Thermo Fisher Connect account.

Instrument Settings and Configuration

Navigating Instrument Settings

Accessing and overview of various instrument settings and functions available.

Network Connectivity and Software Updates

Instructions for connecting to Wi-Fi and updating the instrument's software.

Configuring Date, Time, and Cloud Region

Procedures for setting the instrument's date, time, and selecting the cloud region.

Instrument Maintenance and Cleaning

General Instrument Care and Power

Guidelines for basic instrument care, including power supply and cleaning precautions.

Cell Counter Cleaning and Decontamination

Detailed instructions for cleaning the touchscreen, instrument case, and decontamination.

Troubleshooting Common Issues

Problem Diagnosis and Solutions

Lists common observations, their possible causes, and recommended actions for troubleshooting.

Instrument Technical Specifications

Physical and Performance Specifications

Details on instrument dimensions, weight, operating requirements, and technical specs.

Optics and Analysis Slide Specifications

Information regarding the instrument's optics and the specifications of analysis slides.

Countess 3 Counter and Accessories

Available Accessories and Consumables

List of compatible accessories, consumables, and their catalog numbers for the Countess™ 3.

CSV File Format Definition

CSV Data Structure Overview

Explanation of the comma-separated values (CSV) file format and its data categories.

Safety Precautions and Guidelines

Chemical Handling Safety

Guidelines for the safe handling, storage, and disposal of chemicals and hazardous waste.

Biological Hazard Safety

Precautions and procedures for working with potentially biohazardous samples and materials.

Documentation and Technical Support

Customer Support and Resources

Information on accessing customer and technical support, product documentation, and warranty.

Limited Product Warranty

Details regarding the product's limited warranty coverage and terms of sale.